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Copyright 2001-2018 inclusive   McGowan Marine Design, Inc.

Ghost - a 50’ ocean crossing power trimaran

Ghost was commissioned when the client who wanted Mischief reassessed the time and energy he had to maintain a large cutter and decided an efficient power multihull might better meet his needs. 


The client really liked the beautiful Shuttleworth tri Adastra, but settled on a much more moderate 50’ size, and asked if I could come up with something along those lines that had a simple interior paired with a functional and spacious outside living arrangement. Power is to be a simple diesel and construction strip planked epoxy/red cedar and ‘glass sheathing. Normal operating speed is 14 knots. A cruising range of 2,000 nautical miles at 8 knots was one requirement, seaworthiness and functionality others. 


It had to look cool, too! With lots of input from the client and his very artistic brother-in-law we came up with this shape. 

The main hull is based on a 65’ catamaran I tank tested extensively with a client in 2006. In it the spray rail is actually a full-width deck... chine-to-chine, and the canoe body below it is attached after the upper hull’s construction is finished. This setup allows the cabin sole to be the upper hull’s bottom, simplifying and lightening construction.

Originally, a Mischief Tender was to be the type used for this boat, but an efficient powerboat was required after all and one that fits well in the rectangular tender ‘garage’.  It was the perfect shape for one of my favourite speed boat types - Sea Sleds.   Originally designed by Albert Hickman of Nova Scotia nearly 100 years ago, the speed curve (power/weight) on these boats is incredible and their seaworthiness is legendary. I was able to develop outer spray rails with perfectly straight fore-and-aft keels (compared to Hickman’s angled ones) and a plywood panel construction for lightness, strength, and quick building.  Estimated flat water speed with a 30hp outboard while carrying 4 passengers is 40 knots!

Ghost’s General Arrangement

( Windows version here)

Ghost Quicktime Movie

Dimensions: 14’ x 4’-3” x 6” x 900 lbs loaded displ. ( 4.27m x 1.3m x 0.15m x 408 kg)

A solar/electric drive setup with twin wind generators aft and solar panels was looked at, with a SkySail (or similar) used for downwind passagemaking.  (I like this setup)

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