The theoretical maximum speed that a displacement hull can move efficiently through the water is determined by it's waterline length and displacement. It may be unable to reach this speed if the boat is underpowered or heavily loaded, though it may exceed this speed given enough power. Read more.
Classic hull speed formula:
Hull Speed = 1.34 x √LWLA more accurate formula devised by Dave Gerr in The Propeller Handbook replaces the Speed/Length ratio constant of 1.34 with a calculation based on the Displacement/Length ratio.
Max Speed/Length ratio = 8.26 ÷ Displacement/Length ratio.311
Hull Speed = Max Speed/Length ratio x √LWL
A measure of the power of the sails relative to the weight of the boat. The higher the number, the higher the performance, but the harder the boat will be to handle. This ratio is a "non-dimensional" value that facilitates comparisons between boats of different types and sizes. Read more.
SA/D = SA ÷ (D ÷ 64)2/3
A measure of the stability of a boat's hull that suggests how well a monohull will stand up to its sails. The ballast displacement ratio indicates how much of the weight of a boat is placed for maximum stability against capsizing and is an indicator of stiffness and resistance to capsize.
Ballast / Displacement * 100
A measure of the weight of the boat relative to it's length at the waterline. The higher a boat’s D/L ratio, the more easily it will carry a load and the more comfortable its motion will be. The lower a boat's ratio is, the less power it takes to drive the boat to its nominal hull speed or beyond. Read more.
D/L = (D ÷ 2240) ÷ (0.01 x LWL)³
This ratio assess how quickly and abruptly a boat’s hull reacts to waves in a significant seaway, these being the elements of a boat’s motion most likely to cause seasickness. Read more.
Comfort ratio = D ÷ (.65 x (.7 LWL + .3 LOA) x Beam1.33)
This formula attempts to indicate whether a given boat might be too wide and light to readily right itself after being overturned in extreme conditions. Read more.
CSV = Beam ÷ ³√(D / 64)
A collaboration between designer Doug Peterson and yacht broker Jack Kelly birthed the Kelly Peterson 44, she was quite ahead of her time at her introduction in 1975. A long distance center-cockpit cruiser by design, she has earned a reputation for speedy passages. 180 miles days are not uncommon, with useful performance coming in all wind conditions and points of sail.
Today the design is a classic, Kelly Petersons have traveled far and wide and are often seen in far flung locations the world over, especially in the South Pacific. Many have circumnavigated.
Legend has it Jack Kelly, a San Diego yacht broker in search of his ultimate cruising boat, approached yacht designer Doug Peterson who at the time was already starting to make his mark on the racing scene. The boat he drew for Kelly kicked off a narrative, not all that uncommon in the cruising boat industry. It reminds us of the tales behind the Valiant 40 and the Alajuela 38 to name a couple. In this particular case the plan was to build ten boats, sell nine, keeping one to sail away. A couple of hundred hulls later, Kelly hadn’t left for his voyage but had a thriving boat building business instead.
Kelly’s boats were built by the Taiwanese yard Yu Ching Marine located in Kaohsiung, they built over 200 boats between 1975 and 1983. The boats were then outfitted in the United States or wherever they were shipped. Kelly also built an extended version which was called the Kelly Peterson 46 using another yard, Queen Long Marine, these were manufactured between 1980 and 1990.
Between 1979 and 1986 another Taiwanese yard called Formosa Yachts built an extended version called the Formosa 46, this string of boats eventually become known by the cruising community as “Cheaterson” boats. Digging deeper behind this story, Sea Magazine reported in May 1987 that Kelly had quality problems while building his original molds and had them destroyed, finding an alternative company to build a second set. During the interim the line drawings were stolen. In the months that followed two boats from Taiwan appeared on the U.S. market with a striking resemblance to the Kelly Peterson 44.
From here the facts surrounding the boats become sketchy, some say the original builder Yu Ching built an additional 400 hulls (though we are dubious about this figure). It’s likely that Queen Long and Formosa who built the 46s also built some 44s, and rumours abound that other Taiwanese yards got in on the act of building the 44s and 46s. Such was the case around the Taiwanese boatbuilding industry who had a unique interpretation to the Western concept of intellectual property.
Other examples of the basic Peterson hull design being matched with alternate interior designs were produced under names as Spindrift 46 and the Hillyer 46.
Between the 200 plus genuine Kelly Petersons and copies built by competing yards some estimates put the total of boats in excess of 600.
Probably the most noticeable feature of the Kelly Peterson 44 is a near vertical transom, the boat was designed as a double ender with her transom lopped off, making for an abrupt finish to an otherwise pleasing shape. The bow has a fine entry with a moderate rake and the maximum beam is carried slightly aft of midships.
Below the waterline there’s a fin keel cutaway at the forefoot and aft which reduces her wetted surface, good for both light-air performance and a nimble turning radius. The keel has a relatively long run which helps the boat to track well. A full-size molded-in skeg supports the rudder and provides good protection during the occasional grounding. Protected also is the prop, mounted in an aperture between the skeg and the rudder.
One third of her light to moderate displacement of 30,000 pounds is encapsulated in her ballast slung low on her 6′ 4″ keel. This combined with her clean bow entry helps her produce a nice soft motion.
Above deck the on this center-cockpit boat is a low-profile cabin trunk which is both sleek and practical in that it aids a lower center of gravity. The cockpit is capaciously social with seating for 8 at a squeeze under anchor. The deck layout is good, with wide side decks bordered by 4” bulwarks and comfortingly high lifelines. There’s both bow and stern pulpits. A large cockpit locker provides for deck storage.
Designed for Californian conditions, the Kelly Peterson 44 is driven by a beefy twin spreader cutter rig carrying more than 1000 square feet of canvas, ample for a boat of this displacement. It’s also very manageable for a short-handed crew.
The mast rises 60 feet above the waterline, keel-stepped, with 3/8” cap shrouds, headstay and backstay. The mainsail sheeting line is on the end of the 17-foot boom, which keeps it out of the cockpit area. The original boats had large mainsails going to the end of the boom, which produced too much weather helm, subsequent boats trimmed the length of the foot 30 inches.
Down below there’s a useful three cabin layout (including the saloon) that serves well for both cruising and living aboard. The interior is bright and well ventilated from the three large hatches and twelve portlights. The forward cabin has a vee berth with full standing room and shares an enclosed head with shower aft. The saloon is a bright and open space featuring a straight settee to starboard. Opposite, the main cabin dinette to port has a two position table which converts to another double berth. Centered in the saloon, the keel stepped mast makes for a safe handhold when at sea.
The offset companionway hatch allows for a well-equipped U-shaped galley sited to port and has large capacity refrigeration and a gimbaled stove. The double stainless steel sink is close to the centerline and works well on any tack. Starboard of the galley is a full sized, sit down chart table and electrical switch panel.
Although described by some as a crawl space for the lack of headroom, there is an inside passageway to the aft cabin on starboard which provides access to a large engine room encompassing the remainder of the mid ships beam. The master stateroom aft includes a full double berth, and a private head. Additional access to the aft stateroom is offered through a second companionway from the cockpit.
Access to the bilge and engine is excellent. Most boats had a 62hp Perkins 4-152 Diesel while a few were fitted with a 80hp Ford Lehmans.
The boats were heavily constructed in hand-laid fiberglass matt and roving with polyester resin. Thicknesses range from nearly one inch at the bilges, tapering to 3/4 inches at the waterline and a half inch at the deck. The integral keel encapsulates 10,000 pounds of iron ballast packed with concrete. The rudder consists of a stainless-steel frame, packed with plywood and sheathed in fiberglass. Some of these have been replaced over time after leaks developed and corroded the stainless steel.
The deck-to-hull joint is a lip-tongue arrangement with a wood brace inserted between the joint in some areas, then fiberglassed over. A teak cap rail was screwed into the wood brace. This area can be prone to leaks, especially where long bolts holding the genoa track to the top of the bulwark protrude through into the cabin. The plywood-cored decks were finished in non-skid gelcoat as standard but some were optionally fitted with teak decking.
Overall construction is known to be solid, one story goes that a Kelly Peterson went aground on a reef in the South Pacific. The boat was pulled across the reef over a hundred feet before sailing away.
The original Kelly Petersons were shipped without rigs and then set up where they were delivered, so there’s variations between boats of differing destinations. The Californian boats usually had LeFiell spars and Navtec rigging.
The Formosa boats and those from other yards can have quite different construction details from the Kelly yachts. Kelly had an American overseer in Taiwan who reported construction problems to Kelly and these were repaired when the yachts were delivered to California and instructions then sent back to the yard to correct the problems in subsequent boats. Market prices reflect a higher price on the genuine Kelly Peterson boats, however today the consensus between owners is that the condition of their boats is more of a function of their use and upkeep than original manufacturer quality.
True to Doug Peterson’s reputation as a racing boat designer, the Kelly Peterson 44 is well known to make fast passages. The theoretical hull speed is 8.3 knots and owners report this is possible on all points of sail given the right conditions. 180 mile days are very attainable.
She is well balanced and despite long rudder control lines reaching from her centre cockpit, the feedback at the helm is surprisingly good. The boat is relatively easy to single hand, even in a blow. And importantly, her motion at sea is comfortable.
» The official website of the Peterson Cutter Owner’s Group
» The Kelly Peterson and Formosa owners mailing list hosted on Yahoo Groups.
» Peterson 44 Review by Joe Minick, Cruising World Magazine, November 1997
» The Good-Old Peterson 44 – After 45,000 Miles by Jack Kimball, Blue Water Boats Magazine, May 1998
» Brilliant II, a Peterson 44 by Sharon Smallwood, Cruising Helmsman Magazine, July 2007
» Sea Esta, A Peterson 44 Can Get You Where You’re Going by Zuzana Prochazka, Latitudes and Attitudes Magazine, May 2005
» Sea Magazine a Kelly Peterson article by Peter Bohr, May 1987
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