Bluewater Overview

Adapted from an article which appeared 

in the January 2007 Cruising Club News, 

published by the Cruising Club of America. 

 

Dimensions

Bluewater is hull number 32 of the Nordhavn 47 line of offshore passagemaking power boats built by Pacific Asian Enterprises Inc. (PAE) at the Xiamen, China, factory operated by South Coast Marine.  The boat was built for Milt and Judy Baker,  an experienced mid-sixties cruising couple who sought reliability and comfort in a capable passagemaker.  This model is one of the new generation Nordhavns—big boxy boats, really, with lots of freeboard and loads of interior volume.  With three tons of ballast and heavy loads of fuel, water and machinery, it’s a boat built to go to sea on extended passages and keep its crew safe and comfortable in the process, and provide a nice platform for extended living aboard on the hook or alongside.

As builders of the distinguished Mason line of sailing yachts, PAE also built a strong reputation among sailors.  When the sailing market began to soften in the 1980s, the company continued to build its sailing yachts but hedged its bets by launching its first Nordhavn powerboat in 1989.  That design was the now-venerable Nordhavn 46, created from the get-go as an offshore passagemaker. With its sweeping sheer, long keel, pinched stern, and relaxed lines, it was no accident that the N46 resembled a sailing yacht.  With the N46 for openers, the Nordhavn line found legs in the emerging offshore powerboat market, and it wasn’t long before PAE ceased altogether building the Mason sailing yachts to concentrate on its new line of trawler yachts.  By mid-2006, more than 300 Nordhavns had been built and at least four, including the company’s own Nordhavn 40, had completed circumnavigations.

Some would say that to fall in love with a Nordhavn 47 you have to go beyond “the look” of the boat.  Unlike the N46, the N47 and its sister ships, the N40, N43, and N55, have the austere look of a workboat: high bow, all sharp angles without sheer, and more height and beam than a seaman’s eye might want for the length overall.  Yet many Nordhavn aficionados embrace the broad shoulders and salty, almost commercial look of a Nordhavn--and even the gray color chosen for so many of the hulls.  On the other hand, some of those who love the security and rock-solid systems integrity of a Nordhavn have a hard time liking “the look.”  If function is beauty, it’s easy to argue that the Nordhavn 47 and her sisters are beautiful for, if nothing else, they are seriously functional cruising machines.  Milt says beautiful is a not word he’d use to describe the yacht, but he calls her “salty to the eye and definitely handsome.” 

In real world cruising trim and with a full load of spares and full tanks, Bluewater tips the scales at about 100,000 lbs. At half load, carrying nearly 1,500 gallons of fuel, she has a theoretical fuel burn of 6 gallons per hour at 8 knots, yielding a no-reserve range of just over 3,000 nautical miles.  On long passages where stretching the range is critical, backing her off to 7 knots reduces the theoretical fuel burn to 3.5 GPH, giving a theoretical no-reserve range of 2,740 NM.  With 24/7 (6 kW) generator use and a 10% fuel reserve, the yacht’s theoretical range at 7 knots is 2,530 NM.  

The real world numbers are different.  Crossing the North Atlantic in 2007, Bluewater averaged 5.1 GPH (including generator burn) at an mean speed of 6.6 knots for an average daily run of 159 NM.  Using those proven averages, with a 10% reserve it's fair to say that the boat has an at-sea endurance of 261 hours or about 1723 NM.   (On the long-legged crossing from Bermuda to the Azores, Bluewater reduced speed and fuel burn, averaging 4.4 GPH (including generator use) at 6.2 knots, covering 1820 NM and arriving with almost 200 gallons of fuel remaining.) 

Hull Design

In the May/June 2004 Passagemaker magazine editor Bill Parlatore wrote, “The new Nordhavn 47 is the latest incarnation of the design evolution at PAE.  It represents a new family of passagemaker for the California-based company, and, in many ways, the boat is as different (from) as it is similar to the original (Nordhavn) 46 . . . the new generation of Nordhavns is evidence that more buyers are willing to trade small interiors in efficient hulls for more accommodations, tankage and load-carrying ability.”

As with all of Nordhavn’s recent offshore designs, the 47 uses the company’s trademarked “modified full displacement” hull form, a concept developed and proved first with the company’s Nordhavn 40. The fundamental benefits of full displacement power-driven vessels, of course, include long range, heavy load-carrying ability, economical operation and good offshore performance.   To this PAE added a number of refinements aimed at improving performance. To help reduce pitching motion and improve weight-carrying capacity, the yacht’s beam is carried farther aft than in typical full displacement designs and the stern sections are fuller. The full stern sections also help extend the top end of the cruising speeds by reducing the drag caused by “squatting,” usually seen in full displacement hulls running at near the top of their speed-to-length ratios.

The Nordhavn 47's hull includes a slight tunnel area above the propeller, allowing the boat to slow-turn a large-diameter prop without unduly increasing draft. The large prop reduces cavitation and vibration, delivering a smoother, quieter ride.  Bluewater is fitted with a 34x30 inch propeller running at a reduction of 3.96 to 1, meaning the propeller turns once for roughly every four engine RPMs, close to ideal in a cruising hull.  The yacht’s owners report that this is a very smooth, quiet boat. 

In developing the modified full displacement hull concept, PAE went beyond drawing board theory.  Extensive tank testing at B.C. Research in Vancouver, Canada, water-tested the concept.  Perhaps the most notable feature to come from tank testing is the company’s “maintenance strakes,” gentle bulges in the hull form amidships on either side of the keel, directly beneath the engine. In the Nordhavn 47, this allows the single main engine to ride lower in the hull for better stability, good protection for the propeller, minimum shaft angle and optimum thrust.  The extra space provides another advantage: an engine room with 5’11” headroom. Tank testing also showed surprising 2% increase in overall boat speed at high RPMs thanks to the positive effect the maintenance strakes on the vessel’s performance at higher cruising speeds.  Admittedly, 2% of 9 knots is less than 2/10 of a knot, but the presumption had been that the added wetted surface of the blisters on the hull would cost speed, not add it, so the results came as a pleasant surprise to be sure.

On the downside, tank testing revealed that the full stern sections slightly reduced fuel economy at lower cruising speeds.  PAE founding partner Jim Leishman is philosophical about that, noting that most buyers are more than willing to take advantages of reduced pitch and more load-carrying capacity (including more fuel and longer range) as a tradeoff for the small increase in fuel economy a sleeker hull would bring.  After all, he says, the cost of fuel represents a small part of the overall cost of owning a yacht like the Nordhavn 47.

Some earlier Nordhavn designs are known for their bulbous bows like those on commercial ships. With this in mind, PAE’s tank testing program experimented with different bow shapes, including a bulbous bow.  Typically, a bulbous bow increases hull efficiency by reducing resistance and lengthening the waterline. According to theory, it also dampens pitching motion in heavy head seas. After tank testing in a variety of computer-generated head seas, PAE concluded that adding a bulbous bow to a hull like the N47 created a noisy, concussion effect with the yacht running into up-swell.  As some Nordhavn 62, 57 and 50 crewmembers can attest, this can be more than a little annoying while punching head-on into heavy weather.  The debate about bulbous bows goes on, but the prevailing wisdom seems to be that few boats under 50 feet benefit from bulbous bows.  The N47 and most other new Nordhavns are being built with conventional, non-bulbous bows. 

Bluewater and other Nordhavn 47s are built to heavy scantlings. The hull structure of the 47 is a solid laminate of fiberglass vinylester resin with a network of full-length, longitudinal and transverse stringers for stiffness.  In an offshore voyaging powerboat, P.A.E. considers series of laminates superior to cored construction, especially since reduced weight is not a requirement with full displacement designs. Forward sections feature extra laminates for collision protection, and collision bulkheads and watertight doors are included in the design.

After moving from sail to power in the 1990s, the Bakers owned a Grand Banks 42 trawler for a dozen years, cruising between Havana and Halifax, often spending summers in Maine and winters in Florida and the Bahamas .  They knew themselves and their needs, and they knew that they rarely conned their yacht from the upper station so they ordered their Nordhavn 47 without a flying bridge.  “As a career Navy officer, I spent some years at sea,” said Milt, “and I know first-hand that too much weight topside can result in a rolly, unruly vessel.  Relatively speaking, the 47 is already Nordhavn’s tallest yacht, so we worked hard to reduce added top-hamper and weight up high.”  In addition to forgoing a flying bridge, they chose to bypass Nordhavn’s optional large fiberglass stack, to carry a modest 10-foot RIB with a 15 HP two-stroke outboard, and to install a strong but light davit for launching the dinghy.  With these changes, they saved several thousand pounds of topside weight.   Milt reports this paid big dividends when the yacht sustained a gale off the coast of Portugal in 2007.

Bluewater’s hull, recently out of the mold.  Bulkheads and longitudinal and 

transverse stringers are glassed into place while the hull is in the mold.  

Driving Forces

The single main engine for Bluewater is a non-electronic turbocharged 174 HP Lugger LP668T diesel.  This is a six-cylinder John Deere tractor engine marinized by Alaska Diesel Electric (ADE), the same company that builds Northern Lights generators.  PAE has a long and close working relationship with ADE, and more Nordhavns have Luggers than any other kind of engine.  Nordhavn owners love ‘em, and Bluewater’s owners are no exception.

For a boat that spends most of its time crossing oceans, a 174 HP Lugger main engine is probably a good choice.  The truth, however, is that most Nordhavns and other ocean-crossing power boats spend the majority of their time cruising in coastal waters where speed is often more important than range, and Milt has come to believe that a bit more power would be desirable.  “The Nordhavn 50, an earlier design, was typically fitted with 250 to 300 HP engines, giving it an easy cruising speed of 9.5 knots or more,” he said. “When I see my friends eating up the coastal miles in their Nordhavn 50, I believe that a more powerful main engine would have been a wiser choice on my part.”  To date, however, no N47 has been built with a more powerful engine.

“We made it a point,” Milt said, “not to spec an electronically-injected diesel engine for this boat.  There’s no question that today’s electronic diesels are more efficient across the whole range of power, but in my view reliability trumps efficiency in an ocean-crossing boat.  With this engine, I can work on it myself or find a mechanic in any port to help me out, but electronic engines today are still rare, delicate creatures serviced with proprietary software as often as wrenches.  Trying to get one fixed in far-flung ports is a problem I don’t need!”

Nordhavns are well known as dry stack boats which use keel coolers and send the exhaust out near the top of the mast.  Milt and Judy had years of experience with wet exhaust boats, however, and insisted on a wet exhaust system aboard their N47.  Bluewater was the first N47 delivered with a wet exhaust system: two raw water pickups for the main engine, one each to port and starboard of the keel, a water-lift muffler system, with the raw water and exhaust exiting the hull at the waterline just ahead of the transom on the port side.  The standard N47 sends engine room heat “up the stack,” but lieu of a stack Bluewater uses a large diameter 1,850 cubic feet per minute fan to send pressurized air into the engine room which, in turn, forces the hot air out through a large plenum.  The yacht’s engine room--even in the tropics--rarely exceeds 125 degrees.

Maneuvering a single-screw 100,000-pound yacht in close quarters can be intimidating, so Milt specified bow and stern thrusters.  In retrospect, he says, the boat is so well-mannered a stern thruster has proved unnecessary.  “I’ve learned that in a docking situation this boat does exactly what you tell it to do, responding quickly and easily to helm and thruster commands and staying-put until you tell her to move,” he said. 

In the trawler world, the idea of a separate get-home or “wing” engine remains controversial.  Why, after all, have an expensive hunk or iron that sits mostly unused and gathering rust in the engine room?  Detractors point out that thousands of commercial fishing vessels operate with a single diesel engine and no get-home capability and make out just fine on the oceans of the world.  Yet every Nordhavn owner knows another who has had to use the wing engine after developing a problem that prevented use of the single main engine, transmission, shaft or propeller.  Equally important, perhaps, is that the wing engine is an “expected” option and the few Nordhavns without them don’t sell as quickly on the brokerage market.  In the final analysis, nearly all new Nordhavns are ordered with get-home engines.  The wing engine aboard Bluewater is a 40-HP Lugger diesel with a dedicated transmission, shaft and folding propeller and its own dedicated fuel tank.  In flat water and wide-open-throttle it has been shown to move the boat a 5 knots; in flat seas it can cruise for days at 4 knots on 1.4 GPH--96 miles per day at a cost of 34 gallons per day. That equates to a theoretical no-reserve range of over 4,200 miles!

Steady as She Goes

Almost as important as propulsion in a passage-making powerboat is roll reduction.  Robert Beebe, author of the seminal ocean powerboating book Voyaging Under Power, considered roll reduction hard to achieve yet vital for comfort at sea aboard a passagemaking power boat.  “There were two significant by-products of roll-reduction,” Beebe wrote.  “It made going to sea a pleasure even for persons who had never been to sea before. And it reduced the fatigue factor to just about zero.”

He continued:

“Roll reduction made cruising with inexperienced persons possible as the environment produced by our stabilizing gear proved to be extremely comfortable.  People cruising with us would come to the end of a long voyage and say they had never felt more fit. I finally figured out what was happening.  The ship would always roll slowly, but the roll was not to a degree where you had to hang on, or use bunkboards, or brace yourself in a seat, or anything like that.”

As a member of the organizing committee for the Nordhavn Atlantic Rally 2004 and head the rally’s advance team, Milt used the experience to test the waters to see if a Nordhavn was the right next boat.  Although Milt and Judy flew ahead of the fleet to meet the rally yachts when they arrived in Bermuda, the Azores and Gibraltar, they were at the epicenter of the event and learned much from it.  Lesson One was that the system causing the most trouble for owners was not a Nordhavn system at all--it was active fin stabilizers.  About 30% of the 18 boats crossing the Atlantic on the rally experienced problems with their active fin stabilizer systems.  To be sure, rally crewmembers loved the stabilization, but some were severely handicapped when the systems stopped working and could not be repaired at sea. Based on this, Milt and Judy decided to take a belt-and-suspenders approach; they spec’d robust electronically-controlled active fin stabilizers as a primary stabilization system paired with Nordhavn’s proven mechanical paravane stabilization system as a backup.

“Good stabilization on an ocean-going power boat is a no-brainer, and it’s both a comfort issue and a safety issue,” Milt said.  “The comfort Captain Bebee refers to is self-evident, but the safety issue may not be so apparent. First, there’s the possibility of crew being injured by being thrown around as an unstabilized power boat lurches around in a seaway.  Equally important, however, is making good decisions.  When crew members are dead-tired from being beat-up, especially in big seas, the fatigue factor can quickly lead to bad decisions--or sometimes to postponing decisions at a time when decisive action is needed.”

The Nordhavn Atlantic Rally made it clear that the database on stabilizers for offshore passagemaking powerboats was painfully thin.  Until then stabilizer systems had been spec’d based mostly based on a boat’s length, speed and displacement.  But one corollary to the rally’s lessons learned is this: a stabilizing system that might work fine on, say, a Grand Banks doing coastal cruising for a couple of hundred hours per year will not necessarily keep working reliably on a passagemaker under the continuous stress of crossing oceans.  A larger, more robust, more sophisticated system is needed.

Bluewater’s Naiad 254 stabilizer system is just such a system, designed for vessels 55 to 85 feet.  The truth is that the slower a boat, the bigger the stabilization system it needs. That’s because the motion of the fins through the water actually produces the stabilizing effect--and less boat speed requires larger fins or more stabilizer action.  The net effect: slow trawlers need large fins--and larger, more robust stabilizer machinery to control the fins.  An electronic system to sense the roll and control the stabilizers is often spec’d because it allows greater control.  Over 7,000 miles of cruising and 1,100 engine hours in Bluewater’s first 12 months, the yacht’s Naiad 254 hydraulic stabilizer system and Datum electronic control system worked extremely well, reducing roll and providing a comfortable ride for her crew almost no matter what the sea conditions.  However, on the 2007 Atlantic crossing a failure of a critical Naiad component left Bluewater with only one working stabilizer and the yacht crossed more than half the North Atlantic on a single fin, deploying paravanes for added stabilization when necessary. 

In many ways Nordhavn’s backup paravane system is similar to the stabilizing rigs seen on offshore fishing boats.  Two paravanes or “fish” are towed through the water about 15 feet below the surface, one on either side of the yacht suspended from aluminum spars.  Bluewater’s rail-mounted paravane poles are 24 feet long, meaning that the outer end of each pole is approximately 32 feet from the centerline of the yacht, greatly increasing the lever arm and allowing smaller paravanes to do more work.  Each 35-pound paravane, shaped like a delta wing, is designed to dive down with little resistance when the boat rolls and its pole dips downward.  But on the counter-roll when the pole attempts to pull it back up, the paravane goes flat and resists the pull with great effectiveness; that’s what provides the stabilization.

At first glance the paravane rig looks complex, but to a sailor it’s quite straightforward, using what we commonly know as topping lifts, downhauls, and guys.  The hinged poles are stowed in an upright position tight against purpose-designed spreaders, and the paravanes, connected to the poles by nylon line and light chain, are stowed in stainless steel mounts on the transom.  Launching the paravanes requires dropping the poles, then using electric winches with dedicated wire cables to lift each paravane from its mount, in turn, then slowly lower it away into the water until it reaches the end of its chain.  (Retrieval simply reverses the process.)  To be sure, launching and retrieving paravanes is a two-person job, but it requires more finesse than strength.  The only real trick is to prevent a paravane, while swinging as a pendulum, from taking a bite from the transom or swim platform!

On Bluewater's Atlantic crossing, the paravanes were deployed for days at a time in seas up to 8 to 10 feet and winds up to about 40 knots, the highest the Bakers had on the trip.  The motion, they say, was just slightly “jerkier” than with the active fin stabilizers alone, and they estimate that on the average the paravanes were perhaps 70 percent as effective as the Naiads at reducing roll.  In short, the yacht was very comfortable at sea with using the paravanes for stabilization and the extended sea trial validated their choice of paravanes as a backup system.

One downside of paravanes is the drag penalty they impose.  While the variable displacement hydraulic pump driving the active fin stabilizers uses a few engine horsepower and, therefore, burns a small amount of additional fuel, the stabilizer fins seem to impart no speed penalty.  On the other hand, the Bakers found that their paravanes slowed forward progress by .25 to .4 knots, a 4 to 6 percent speed loss assuming a nominal 7 knot speed of advance.  That equates to a loss of 6 to 10 miles a day on a passage, an easy fare to pay if the alternative is no stabilization.   

Cruising in the Mediterranean, the yacht's owners have found another use for the paravane poles: deploying a flopper-stopper to reduce roll at anchor.  This simple stainless-steel device works to break the rhythm of the roll, and deploying a single one up swell usually does the trick.

As a side note, Bluewater’s owners say that no system on the boat attracts as much attention as the paravane rig.  Dock walkers frequently stop to study the paravanes, poles, and associated rigging.  Often, one will try to explain the system to another, and the owners can’t help but chuckle when they frequently see the explaining dockwalker with arms stretched wide, slowly flexing from right to left and back again as part of the explanation.  Judy calls the pier-dance “doing the dippity-do.”

Electrical

While there’s a standard electrical plan for the Nordhavn 47, in reality Nordhavn electrical systems are individually designed for each new buyer’s needs.  Milt met with the system designer to review the standard plan and make additions and amendments.  To facilitate use of the boat in ports away from the U.S. electrical grid, the yacht’s 120-volt AC load is powered by a 4 kW Xantrex inverter.  Whether the yacht is at anchor with no incoming power or plugged into shorepower, that means refrigerator, freezer, microwave, AC lights and electrical outlets all receive clean, conditioned power directly from the inverter.  It also means that in a 230-volt, 50-hertz electrical environment like that found in Europe, normal U.S. household appliances can continue to be used because they receive their power from a 60-hertz inverter, not directly from the shorepower. Two  dedicated Mastervolt battery chargers are used to charge Bluewater's batteries in a 50-hertz environment and, in turn, the batteries supply power to the house load through the inverter.  In case of inverter failure, a bypass that allows operating the house AC system directly from either shorepower or generator.  In practice, the owners found making the transition from American to European power as easy as having new electrical cords made up with European male fittings.

Bluewater is the first N47 with two generators in the engine room, and it was a tight fit leaving no room for sound shields.  The lack of sound shields, however, has not proved to be a problem because sound insulation throughout the boat keeps noise levels low.  Sitting in the main salon immediately above the generators, one can barely hear a genset running.  The generators are a 12 kW and a 6 kW Northern Lights, and during the yacht’s first two years of operation the 6 kW genset accumulated close to three times as many hours as the 12 kW.  The six sips ½ gallon per hour, yet it will carry the house load and run up to three air conditioners.  The 12 kW generator is put online to recharge the batteries using both Mastervolt battery chargers charger while using air conditioning, washing or drying clothes, heating water, or running heaters.  Underway, the house load is supported by the Leece-Neville 175-amp 24 volt charger on the main engine.  In fact, if there’s no need for 240-volt service (air conditioners, watermaker, washer and dryer), when the yacht is underway the big alternator easily carries the full house load and keeps  batteries topped off.

The DC electrical system aboard Bluewater pairs 12-volt batteries for banks of 24 volts. P.A.E. equips all new Nordhavns with maintenance-free LifeLine brand absorbed glass matt (AGM ) batteries, and it’s a good thing. Bluewater’s battery banks contain a total of 16 12-volt batteries, most of them out of sight beneath shelves in the lazarette, meaning that adding water would be nigh-unto impossible.  In addition to the 24-volt banks, the yacht has two 12-volt banks: the 6 kW generator starting battery and a pilot-house communications battery which powers all radios and the satellite phones.  Bluewater’s batteries are shown in the following table.

For safety, P.A.E. locates all battery disconnect switches outside the engine room.  Bluewater’s are well-labeled and mounted on the forward bulkhead in the lazarette, making access easy in the event of an emergency.

Milt and Judy enjoy being at anchor for days at a time.  In the Mediterranean in summer 2007 Bluewater went for about without ever stopping at a marina or pier for electricity or eater, depending on her batteries, generators and watermaker the whole time.  The yacht can remain at anchor without recharging for up to 18 hours, but batteries are typically charged twice a day.  Milt monitors the Victron Energy BMV-501 battery monitor carefully, generally starting a genset to begin charging the house bank batteries before they get down to about 60% of capacity.  Using both Mastervolt chargers together, batteries can be charged at a starting rate of about 130 amps at 24 volts, but that quickly tapers off.  To assure long life the AGM batteries should be recharged to a full 100% at least once or twice a week, and to accomplish this typically, Milt has found it takes running the generators and chargers 3-4 hours at a time.  Normal protocol is to start with the 12 kW generator (burning about 1 GPH) for one to two hours of charging, usually running the watermaker and sometimes the washer and dryer at the same time.  Once the load tapers, the more economical 6 kW (½ GPH) generator is used for the balance of the charging.  This approach consumes less fuel and keeps generators loaded appropriately.  At anchor in the Mediterranean, the Bakers find that Bluewater uses about six to eight gallons of diesel per day for charging, refrigeration, making water, laundry and all other house services.

Like other systems aboard Bluewater, the AC and DC electrical systems have proved to be virtually 100% reliable.  One Nordhavn owner 47 calls the yacht’s complex AC-DC system a “world class electrical system,” and Milt and Judy agree. 

Plumbing

The Nordhavn 47’s plumbing system has also proved to be well designed and almost trouble-free in two years of almost continuous use.  The bilge pump system provides a good illustration of P.A.E.’s approach.  The standard N47 is delivered with two electric bilge pumps, one for the deep bilge and one for high water, plus a backup manual pump--all standard.  The deep-bilge pump is a 24-volt Jabsco diaphragm pump with a capacity of 10.8 GPM , powered through a bilge pump panel in the pilot house and operated by an auto-on-off switch--though thanks to its head the actual capacity is closer to 5 GPM.  A red status light on the bilge pump panel illuminates to alert the person on watch whenever the pump is operating, and Bluewater’s optional bilge pump counter displays the number of times the pump has cycled on since the display was reset.  A Groco bilge starainer is at the lower end of the main bilge pump hose.  A second bilge pump, the high water pump, is a 24-volt Rule submersible pump rated at 3700 GPH or about 60 GPM, though head probably reduces this to 30-40 GPM.  This is also powered through the pilothouse bilge pump alarm panel and operated by an auto/manual switch, with a red light similar to the one for the normal bilge pump. In addition to starting the stopping the high water bilge pump, the switch activates a piercing audio alarm (silenced at the touch of a switch) any time the high water pump is pumping.  Prior to crossing the North Atlantic in 2007, the Bakers added a second high water pump, an identical 3700 GPH Rule pump.  The fourth or “backup for the backups” bilge pump is a heavy-duty Edson 638 hand-operated diaphragm pump located high in the engine room and accessible from the main saloon.

When it comes to tanks, PAE ’s approach is to build what it calls “lifetime tanks” of fiberglass, pressure test them to 4 PSI , then glass them firmly in place.  No rusty tanks on these boats!  Bluewater has two main fuel tanks of about 700 gallons each, a 400-gallon water tank, a 120-gallon holding tank, and a 110-gallon gray water tank, all fiberglass.  Fuel tanks have large access plates allowing an average-sized man to climb inside, and fiberglass 

A 400-gallon fiberglass fresh water tank for a Nordhavn 47 (foreground) awaits pressure testing and gel coating at the factory. In the background is a 700-gallon fiberglass fuel tank.  

baffles are bolted in place--each can be removed with a pair or wrenches, giving access to every corner of the tanks.  Fills for the water and fuel tanks are conveniently located above deck level, reducing the likelihood of seawater intrusion.  However, plumbing from filler to tanks goes through a series of turns and the vent hoses are small, making filling water and fuel tanks a bit slower and more of a chore than it ought to be.  Still, in running several thousand gallons of fuel through the tanks, Bluewater’s owners have never had a fuel spill and have never had a serious problem filling tanks.

The fuel system aboard Bluewater and other late model Nordhavns is straightforward and elegant, developed, shaken down, and improved with input from owners over many Nordhavns.  Bluewater’s two large fuel tanks, one each port and starboard, have valved sight gauges showing the amount of fuel remaining.  These tanks gravity feed through valves to an aluminum 70-gallon day tank mounted on the centerline of the boat. With the day tank mounted significantly lower than the bottom of the wing tanks, every last gallon of fuel can gravity-feed into the day tank.  Selecting appropriate valves, it’s easy to supply the day tank from either or both of the main tanks.   All fuel for the main engine and both generators is taken from the day tank, and fuel returning from those units is returned to the day tank.  The day tank has three features of note.

• A Racor model RK3056 water detection kit, which sounds an alarm and illuminates a red light on the pilot house panel to denote the presence of water in the bottom of the day tank. 
• A small sump at the very bottom that is valved, allowing the operator to take a sample from the bottom of the tank--something Bluewater’s owners do before heading offshore--or to drain off water or dirty fuel. 
• A three-gallon supply reservoir at the top, with a calibrated sight gauge, making it easy to measure fuel consumption over, say, six-minute period then multiply times 10 to obtain a real-time gallons-per-hour reading on fuel consumption.

The dual Racor filters and vacuum gauge for the main engine (right) for fuel transfer and polishing (left).  The transfer pump is at the far right.

A dual 75/900 MAX Racor filter/water separator rated at 180 GPH handles fuel going to the main engine, a bit of overkill for an engine typically operated at well under 9 GPH!  Milt uses 10 micron filters (the same rating as in the secondary filter on the engine) in this unit which has two separate elements together with a four-way valve allowing filter elements to be changed easily while the vessel is underway.  Fuel can be transferred between the tanks and “polished” along the way using a 60 GPH Walbro 24-volt fuel transfer pump and dedicated model 500MA Racor filter also rated at 60 GPH using 2 micron elements. 

Fresh water capacity is 400 gallons, a big load for a 47 foot yacht.  The Bakers report that they somehow manage to use a lot of water, and they get a lot of use from their 600 gallon per day Village Marine Tech watermaker.  Bluewater’s fresh water jet Headhunter heads use ½ to ¾ gallon per flush and the clothes washer uses up to 30 gallons per load.  Bluewater’s pressure water system employs a pair of Headhunter 24 volt pumps, a primary and a backup plumbed in parallel, along with separate breakers and a manifold allowing a quick switchover in the event of pump failure.  Because the vessel’s Headhunter toilets require considerable pressure, the domestic water system is operated at 70-80 PSI , and during the first two years both the pumps and the Whale brand hoses and fittings have handled the pressure without problems.   Bluewater is also fitted with a Headhunter 24-volt salt water pump and associated plumbing to allow salt water to be used to flush the heads, a great water-saver while crossing oceans or anchored in clean, clear water.

Lavatories and showers for the master and guest staterooms on the lower level of the yacht are below the waterline, and Nordhavn’s solution to draining those is sending the effluent  to a gray water tank low in the hull.  The tank is fitted with a pump that automatically discharges gray water when it reaches a certain level.  The black water holding tank, on the other hand, must be pumped overboard by switching a breaker.  Both tanks have 24-volt diaphragm pumps and backup hand pumps, and both can be emptied via deck pumpout.  Both tanks have TankWatch monitors, showing the tank levels at all times; the main water tank level has a conventional electric gauge.  Of course, heads have three-way valves allowing sewage to be pumped directly overboard when offshore or to direct sewage to the holding tank.

Hey, Look Me Over

Approaching Bluewater, the first thing impression is that this is one broad-shouldered, massive 47-footer.  The foredeck is a full eight feet above the waterline, meaning the boat can punch into a serious head sea and still keep the windshield dry.  The design incorporates a wraparound Portuguese bridge with 36-inch bulwarks topped with 1¼-inch stainless steel rails on three sides of the pilot house, a perch weather-deck perch in heavy-going.  The reverse slant of the pilothouse windows and a 15-inch coachroof bill above help keep the sun at bay and reduce spray on the windshield.

Bluewater’s foredeck, showing the raised and dammed platform for ground tackle, the Freeman hatch to starboard leading to the chain locker, and the 30-inch stanchions and rail. Red LED fixtures, two visible just beneath the first stanchions aft of the bow pulpit, light the foredeck and other deck areas.  The shank of the yacht’s secondary Fortress FX-55 anchor is at the left left of this photo.  The large hatch at the left of the picture leads to the forward head.

Ground tackle is easily handled aboard Bluewater, but the design of the anchor-handling system could be improved.  The stout fiberglass and stainless bow pulpit has two bronze rollers to accommodate either a pair of modest sized anchors or a single large one, but it does not have the width to accommodate two large anchors.  In this area Bluewater carries a single Delta 110 lb. anchor secured to 400 feet of 3/8-inch high test chain.  The angle of the bowsprit and rollers is such that the Delta is not self-launching—it must be given a push.   Bluewater’s second anchor, carried in chocks on the foredeck, is a Fortress FX-55.  The Fortress can be quickly connected to its own dedicated rode, 35 feet of 3/8 inch high test chain and 400 feet of one-inch, 16-strand Yacht Braid.  Below-decks, the anchor rodes are stowed in a massive chain locker ahead of a collision bulkhead.  The chain locker, large enough to accommodate two men, is accessed through a 20-inch Freeman hatch on the foredeck.  Bluewater carries several other anchors with their own rope and chain rodes. The windlass is a 24-volt vertical Maxwell 35 with a maximum pull of 3,500 lbs., and a Lewmar anchor chain counter display in the pilot house provides a real-time count of the amount of chain deployed.  High pressure fresh and saltwater outlets and hoses are available on the foredeck for anchor washdown.  One especially well-conceived feature is the raised deck immediately aft of the anchor platform; this is dammed at its after end and has two drains, meaning most muddy water from the anchor chain is confined to the forward 2½ feet of the foredeck before it drains overboard.

Access to the foredeck from the Portuguese bridge is via a hinged door in the Portuguese bridge combing.  Bluewater’s foredeck, surrounded by 30-inch high 1¼-inch diameter stainless steel stanchions and rails, has two large self-draining lockers for fenders, docklines, cleaning gear, or other deck gear.  Both are gasketed and have proved watertight, even in heavy going.  Inside the Portuguese bridge are two smaller lockers.

Moving aft from the port side of the Portuguese bridge provides access up five steps to the boat deck, which is home for the yacht’s Nautica 10-foot RIB with its two-cycle Yamaha 15 outboard.  This rig can be launched in five minutes or less on either side or over the stern, using the hydraulic-electric 1500-lb. Steelhead davit, mounted amidships aft on the boat deck.  The boat deck is also home to two six-foot fiberglass deck boxes.

The Nordhavn 47’s deck and cabin arrangement is an asymmetrical design, with the main saloon offset to port.  Five steps down from the bridge deck level, the starboard side main deck offers a secure 17-inch wide walkway with 37-inch bulwarks topped by 1¼-inch stainless steel rails continuing all the way to and around the after cockpit.  Three hinged fiberglass doors provide access to the pier: from the starboard side bridge deck level, starboard side on the main deck, and in the transom for Med-mooring situations.

Windows and doors to the accommodation are heavily-built aluminum Diamond Seaglaze brand, proven over many Nordhavns, with ½-inch tempered glass.  Bluewater carries large Plexiglass storm shutters for the six side windows in the main saloon; the storm shutters bolt in place and can be installed in 45 minutes, something Milt and Judy accomplish before leaving on offshore passages.  The two pilot house doors and single main saloon door are Dutch doors, meaning the bottom can be left closed with the top open.  The three doors are easily dogged against large diameter rubber gaskets to keep water on the outside. Windows and doors have proven leak-free during Bluewater’s first year.

By any measure, the cockpit would have to be considered small, measuring about 14 feet wide by a scant 5 feet long.  It has 40-inch bulkheads and is about 2/3 covered by the coachroof to keep crewmembers dry while they fumble for keys in the rain.  It’s also self-draining through large scuppers.  The cockpit is also home to the after control station, covered earlier in this article.  A 33x48-inch fiberglass hatch in the cockpit provides access to the lazarette.

Because of the yacht’s asymmetrical design, lying portside to a dock is difficult--the only access is via the swim platform and through the transom door, something challenging if the dock is more than a foot or two above the waterline.  For that reason, Bluewater’s owners always request a starboard side tie, backing into the pier.  Linehandling is easy, and the usual protocol calls for bow lines, a forward-leading and an aft-leading spring at the amidships hawse, and two sternlines running aft from the hawse at the center of the transom.  Once the yacht is secured, the aft leading spring is usually removed to clear the main deck opening door and because the sternlines easily do double duty as an aft-leading springs. 

What’s Inside?

Quality joinery is one well known hallmark of a Nordhavn yacht, and it’s evident everywhere one looks in Bluewater’s accommodation.  Corners are properly radiused, sturdy sea rails double as grab-rails, and interior paneling is made entirely from grain-matched teak veneer, the matched grain carrying through the entire yacht.  A semi-gloss finish shows off the joinery to advantage.  Galley and head counters aboard Bluewater are owner-selected granite.  It may seem a shame to cover the hand-fitted solid teak and holly sole (this is not veneer, folks!), but the owners like the softening and good footing the carpet provides. Interior lockers, drawers, and stowage spaces easily gobble up all the spares and cruising stuff a cruising couple can muster. All drawers and opening cabinets are equipped with positive-lock push-button closers.  

Entering the bright main saloon via the cockpit door, on the port side two reclining leather chairs are separated by a small built-in table, and to starboard is an Ultrasuede-upholstered dinette which seats four.   Bluewater’s owners have had an extension to the table designed, allowing the dinette to seat six by adding two seats on the inboard side.  Directly outboard of the dinette is a 32-inch flat screen television which disappears beneath the settee at the touch of a switch.  The boat carries a SeaTel satellite television system with a 24-inch dish able to receive signals in the U.S. , the Caribbean and Europe .  Eight Diamond Seaglaze windows, four of them opening, provide light and ventilation.  

The main salon opens into the U-shaped galley, and the two rooms are perceived as a single space.  The galley measures 6½ by 8¾ feet and boasts 22 square feet of counter space. It’s outfitted with premium home-style appliances including a 15-cu. ft. refrigerator with two freezer drawers and icemaker, four-burner LPG stove with oven, convection- microwave oven, trash compactor, and disposal.  Milt calls it a “a two-butt galley”, offering room for two people to work side by side.  An apartment-size washer and dryer, the latter externally vented, are nicely hidden away behind a door opposite the galley.  A separate freezer is located forward of the pilothouse.  

If this galley looks larger as compared with most Nordhavn 47s, that's because it eliminates the bulky cabinetry which surrounds the dry stack at the inboard end of the galley counter.  In addition to producing a quieter accommodation, the yacht's wet exhaust increases counter space and makes the main saloon/galley area feel considerably larger.

Up five steps is Bluewater’s command center, the pilothouse.  Height of eye at the helm station is 11 feet above the LWL, giving a horizon of about 3.75 NM, and providing good sightlines ahead and to port and starboard, with, count ‘em, 14 windows around the pilot house.  Sightlines aft are obstructed by the stack and dinghy, so an aft-looking television camera provides a convenient “rear-view mirror.” Visitors say the helm area reminds them of a ship, with it’s comfortable Stidd chair facing a wraparound dashboard with plenty of room for electronic displays.  A detailed look at electronics is beyond the scope of this article, but the electronics aboard Bluewater were selected with redundancy in mind: two radars, two electronic charting systems, two autopilots, two VHF radios, two satellite telephones, three depth sounders, and two AIS units (a transceiver and receiver) among other electronics.  Familiar brand names include Nobeltec, Furuno, Simrad, Icom, and Standard Horizon.  “Over our two years and first 14,000 miles, our electronics have proved easy to use and very reliable,” said Milt.  “Our initial choices on the major components have proved to be good ones, and I am especially pleased with the late addition of a new Furuno AIS tansceiver--it certainly proved its worth on our Atlantic crossing!” 

Aft of the helm station is a settee aft of an L-shaped table, a perfect perch for crewmembers not otherwise occupied because it’s just aft of the pitch axis so motion is minimized.  The settee comfortably accommodates three, but more can squeeze in a couple more when necessary.  Aft of the settee is a three-by-six-foot berth for off-watch crew.  When Bluewater is underway, this berth is often occupied by Katy, the Bakers' 14-pound Schipperke. 

The forward stairway leads nine steps down to the yacht’s two sleeping areas, a master stateroom aft and a forward guest stateroom which doubles as an office.  Each has its own head and enclosed shower.  The master stateroom, with a centerline queen-sized berth, is located amidships, where motion is the least; the pillows are just aft of the pitch axis.  The master stateroom is immediately forward of the engine room, yet the honeycombed Nidacore^® bulkhead and deck beam insulation render engine noise is barely perceptible.  The forward or guest stateroom has a double bunk to port, with a hideaway pipe berth that can be easily deployed above.  To starboard in the guest cabin is a desk and built-in seat, together with file drawers and bookshelves, making it an ideal onboard office.  Drawers and hanging lockers in both staterooms are generous. 

The guest stateroom area receives light and ventilation from three overhead opening hatches and four ruggedly handsome four-dog opening ports, but the master stateroom, tucked beneath the pilot house, is darker—a small optional opening hatch brings in air and some light from the Portuguese bridge, and two opening ports to port and a single one in the head to starboard also provide light and ventilation.  A fan brings in fresh air from the Portuguese bridge, a good addition say the owners.

Overhead and bulkhead lighting is by Cantiluppi and is thoughtfully placed throughout the yacht, with special attention to reading lights in all the right places.  Night lighting inside and out is provided by red LED fixtures an inch off the deck, making it easy to see where one is stepping but equally easy to not to hinder night vision.  On the other hand, the white steaming light on the mast originally cast a distinct glow on the foredeck, hindering night visition so Milt had a composite shade for the steaming light fabricated and installed, a "fix" that he reports worked well.

Air conditioning is one of the yacht’s strengths: a total of 60,000 BTUs worth!  Bluewater carries separate compressor units and air handlers for main salon, galley, pilot house, master stateroom, and guest stateroom.  The air conditioning units are all reverse cycle, offering heat in seawater down to about 50 degrees.  Air conditioning condensate is plumbed to drain either overboard or into the gray water tank, depending on the location of the unit; no condensate drains to the bilge.  Milt modified the air conditioning system to use two separate raw water pumps, one serving the main saloon and pilothouse and the other serving the two staterooms.   That means this yacht can draw less power from the pier while running air conditioning, a serious issue in Europe where 16 amps (at 230 volts) is often all that's available.  It also means Bluewater can run easily on 30 amp power in the USA.

Bluewater’s boat deck, aft of the pilot house and up three steps on the port side, easily accommodates the yacht’s 10-foot tender and davit, plus two deck boxes.  The yacht’s boom has been raised to a position about six feet above the boat deck, making dinghy handling and other boat deck gymnastics easier.  

There's more to this boat than can be covered in a single article, much of it in the modifications Milt and Judy have made.  But the bottom line remains the same: the Bakers report that after two and one-half years of ownership of Bluewater, they're delighted with their choice of a Nordhavn 47.  "This is an ideal boat for our present needs," Milt said.  "I hope we'll own her for a very long time."

Copyright © 2008 Bluewater Navigation Inc.

Comments?  Corrections?  Contact:  miltbaker@mindspring.com