Appendage Refits

Are you looking to increase your sailboat’s performance by replacing that old, heavy, inefficient keel or rudder? VGYD offers state-of-the-art appendage refits, whether it’s a light weight composite rudder, a lifting or canting keel arrangement, or the reconfiguration of an existing keel, our proven foil geometries are engineered and optimized to give you the desired results.

This may be for practical reasons (e.g. reducing the draft on a deep keel); for a performance gain (e.g. a modern more efficient foil design on an older boat); a rating enhancement (e.g. PHRF, IRC, or any other commonly used handicap system); or any combination of these.

Lager 45 (Wild Woman)

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This custom 45 foot cruiser/racer was designed by Rob Ladd, engineered by Van Gorkom Yacht Design, and built by Wiggers Custom Yachts in Canada. After the boat’s first season VGYD was asked to design a new composite rudder that would improve the boat’s tracking ability and windward performance. The new geometry was a deeper, higher aspect ratio blade capable of generating substantially more lift. Both the blade and stock were fabricated from carbon fiber making for a lighter structure than the original configuration. Vision Yachts, on the Isle of Wight, was contracted to do the work. The racing on Wild Woman to date has been excellent with great performances in the Round-the-World Cruising Rally, as well as many Caribbean racing series.



Van Gorkom Yacht Design was sub-contracted by Sponberg Yacht Design to create and engineer a whole new keel with a “beaver tail” bulb for the 80ft cruising ketch Zanabe, which was undergoing a complete refit at the then Little Harbor Boatyard in Portsmouth, Rhode Island. The keel, weighing 38470 pounds (17450 kgs), is an integral lead casting poured around a stainless steel cage with 16 x 1-1/2″ bolts. The fabrication was done by Broomfields in Providence, Rhode Island.

Skye 51

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The owner of this successful Rob Ladd designed production cruiser, undertook a major refit of his boat, which included upgrading to a new spade rudder. VGYD determined that by removing the skeg and replacing the old “barn door” rudder with a more efficient carbon fiber blade and rudder stock, over 300 pounds of excess weight could be taken out of the after end of the boat. The result was a well balanced and maneuverable helm that had a positive impact on the boat’s overall sailing and motoring performance.

Deerfoot 62

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This has been a long term project for this owner who acquired a fiberglass hull several years ago and has been building and outfitting the boat as a world class cruising yacht. Van Gorkom Yacht Design was contracted to design and engineer a new keel and rudder for the boat. The large trapezoidal shaped keel was fabricated in aluminum with integral 200 gallon fuel tanks and 13650 pounds of internal lead ballast. The structure was built by Kanter Yachts in Ontario, Canada. The spade rudder has an aluminum stock and internal frame, has a milled foam core, and fiberglass skins. VGYD also designed the auto pilot tiller arm for the boat.

Gunboat 62 Catamaran (Prana)

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Van Gorkom Yacht Design was approached by the owners of this fast and power catamaran designed by Morrelli & Melvin, to re-engineer the rudders and bearing system on their boat. The redesign constituted a complete revamping of the bearing materials used in the Vera rudder system where a composite of stainless steel and Nylatron was used in combination with polycarbonate ball bearings. These bearing units were fabricated by CAM Engineering in Bristol, Rhode Island. In addition, the dagger board type rudders were redesigned with a new geometry and carbon fiber laminate, which were built by Stew Wiley of Portsmouth, RI.

Tahini 50 Catamaran

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The owner of this Wharram designed 50 foot catamaran came to VGYD with a balance problem. After some consultation and a rigorous study of the boat’s sailing characteristics, we determined that a set of dagger boards would have the greatest effect and would not be detrimental to the flow around the keels. The trunks, made of plywood and fiberglass, were positioned to the side of the hulls with minimal impact to the interior volume. The 8.7 foot long foils were fabricated from fiberglass with a wood and foam core.

McCurdy & Rhodes 46


Sister ship to the famous Carina, this elegant 1970’s racing sloop is under going a major refit, which includes a new interior, a new deck arrangement, a new rig, and a new rudder. The new high aspect ratio, semi-skeg rudder will replace an inefficient trapezoidal geometry with very little increase in wetted surface. The new blade will also put area in way of the propeller, greatly improving the maneuverability of the boat while under power. In keeping with the structural essence of the yacht, the rudder and stock will be fabricated from aluminum and the work will be done by Island Boats in Louisiana.

Swan 391

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Faced with the choice of either selling his boat or reconfiguring the keel due to a local draft constraint, the owner of this Swan 391 contracted VGYD to help him explore the options. We suggested a reconfiguration without the expense of removing the keel from the boat. This was done by cutting 12″ off the bottom, creating a port and starboard plug of our dolphin bulb with the mating surfaces shaped to the bottom of the keel, casting the lead in two halves and bolting the halves to the keel. The work was done at Burr Brothers in Marion, Massachusetts. The result was a zero loss in righting moment and a gain in performance as the boat seems to climb to windward better than it did before.

Frers 55 (ex. Cannon Ball)


Giving old racing yachts a new lease on life has become a very popular and cost effective way to own a high performance sailing boat. VGYD has undertaken several foil refits of some real racing legends such as the Frers 55 Cannon Ball. For this refit we reduced the draft by cutting away 28″ from the bottom of the keel and bolted on a customized 4300 pound “dolphin” bulb. This arrangement was extremely successful in reducing the draft without sacrificing righting moment or performance. A similar keel reconfiguration was designed for the Frers 45 (ex. Springboc).

Andrews 30 (FLAK)


This Great Lakes racer had an impressive record under the MORC rule. However, to make the boat competitive under the local PHRF system the owner of Flak approached Van Gorkom Yacht Design for the design of a new “L” keel. This configuration helped reduce the weight and wetted surface without sacrificing righting moment, for an overall performance gain. In order to accept the keel flange VGYD had to engineer the modification to the structural keel grid. The 2570 pound (1165 kgs) keel, fabricated by Mars Metal of Canada, is a lead fin with a ductile iron internal structure and a lead bulb.

KZ5 (12 Meter Class - "Hizzar")

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America’s Cup yachts of yesteryear are getting well deserved make-overs as their new owners enjoy competitive racing in the various divisions of the 12 meter class. Van Gorkom Yacht Design has been involved in a couple of those refits and one was where the firm was sub-contracted by Perotti Performance Design to engineered the structures for a new composite trim tab and rudder for Hissar, the first Kiwi “plastic fantastic”, KZ5.

Mount Gay 30 (Redrum)

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The owner of this boat bought an incomplete hull and deck from New England Boat Works and has proceeded to finish it off himself. NEB recommended he contact VGYD for the design and engineering of the keel and rudder systems, which were not included with the original package. Given our experience with this size range of racing sail boat, we were able to produce foil designs that complimented and enhanced the overall sailing ability of this boat. The carbon fiber rudder assembly, including blade, stock, bearings and tube were built on the West Coast at ACC Marine. The steel fin and lead bulb “L” keel was fabricated by Duro Keel in Mexico. Redrum was the winner of the 2011 Chicago NOOD and the 1st in division and 3rd in fleet for the 2011 Queen’s Cup.

Thompson 35 (Rumours)


The local Newport racing scene is extremely competitive and few skippers are more competitive than Tim Woodhouse of Hood Sails. Tim’s boat, Rumours, underwent an extensive refit in the spring of 2007 and VGYD was hired to redesign the keel. This involved a full-length trim tab and a new geometry for the T-bulb. The boat was splashed for the latter part of the season, but so far the results have been dramatic. “This boat has never gone this well to windward, and it balances so nicely with the trim tab”, says Tim Woodhouse.

35XS (Paquita)


Launched in 2007, this high performance race boat, designed by Van Gorkom Yacht Design, has established a solid presence among the Lake Baliton sailing elite (Hungary). This past winter the owner refitted the keel with a new trim tab fin and T-bulb arrangement giving the boat even more of an edge on the beat to the windward mark.

US-61 (12 Meter Class - "USA")

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USA, designed by Gary Mull, was a contender in the 1987 America’s Cup in Fremantle, Australia. The boat now competes in the Grand Prix Class in Newport, Rhode Island. Pedrick Yacht Design was asked to design a new carbon fiber rudder with the ability to adjust the balance of the blade. VGYD was asked to assist with the engineering and surface geometry of the stock and foil. The rudder was fabricated by Composite Solutions Inc.

Jutson Mount Gay 30 (Warrior's Wish)

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On its return trip from Hawaii, after having placed 2nd in the double-handed Transpac Race, Warrior’s Wish lost her keel 800 nautical miles from San Francisco. Due to the skill of the crew and luck with the weather, the boat made it back safe. The owner of the boat turned to VGYD to design and engineer a replacement keel that is both lighter and much better balanced than the original. The new “L” keel has a integral stainless steel fin and flange fabrication bolted to our highly efficient dolphin bulb arrangement.The steel fin and lead bulb “L” keel was fabricated by Duro Keel in Mexico.

Maxie Yacht (Nirvana)


This 1982 IOR Maxie yacht, designed by David Pedrick has had a long history of blue water racing in classic ocean regattas including the Sydney/Hobart and the Newport/Bermuda Race. VGYD was tasked by Pedrick Yacht Design to assist in the engineering of a new carbon fiber blade, stock and bearing system when the original aluminum rudder was found to be structurally unsound. The new rudder was built by Composite Solutions Inc.


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When it was discovered the original aluminum keel structure of this Newport sailing charter yacht was showing serious signs of deterioration, VGYD was commissioned to design and engineer a new keel. Working with New England Boat Works, the owner, and the US Coast Guard, VGYD produced a design that was not only stronger and more efficient through the water, but had almost exactly the same physical parameters as the original, which side-stepped a lengthy plan approval process.


The owners of Bella, a custom 33 footer designed byRoger Martin, approached VGYD in the fall of 2015 about helping them optimize the performance of their boat. Those discussions lead to the redesign of the carbon fiber keel fin. The modifications included a trim tab incorporated into a high-lift, laminar-flow section built over the original structure and used the existing T-bulb (see testimonial)

Itinerant 42

A labor of love, the Itinerant is a 42 foot, owner-designed, owner-built, strip-plank and veneer wood epoxy composite ketch. The boat is approaching its final stages before completion and the owner requested VGYD to validate existing boat scantlings, and design and engineer the 4.5 tonne lead fin keel. The keel was cast by Mars Metal.