25-Foot High Efficiency Cruiser

Shearwater is a high-efficiency light weight cabin cruiser.  The design started out as a concept for a commuter that Paul drew up for a potential Seattle area client, and which incorporated some elements learned from experience with Nemo. I modified the commuter concept for family camp cruising by raising the foredeck, completed the detailed design work, and built a prototype which was launched in 2006.  The boat carries a 60HP four-stroke outboard and weighs 2,250 lbs (1,021 kg) all up. It cruises comfortably without pounding at 16 knots, and more efficiently at 13 knots. Fuel consumption at 13 knots is just over 2g/h (7.6 liters/hr).  After a recent 690nm trip to Desolation Sound in Canada, consumption was 1.6gal/hr (6.1 liters/hr) or 6nm/gal (1.6nm/liter) at an overall average speed of 9.6 knots. There is a floodable ballast tank for better sea-keeping in higher sea states, easier docking and a more comfortable ride at anchor.  The cockpit is self-draining and water tight, and the transom is kept low for easy beach and water access. The cabin is a simple V-berth with lockers and a porta-potti. The boat can be easily trailered on a single axle trailer pulled by a six-cylinder vehicle.

-Eric

Particulars

LOA:25 ft (7.6 m)
Max Beam:7’-3” (2.2 m)
Displacement, Max:4,000# (1,814 kg)
Displacement, Lightship:2,019# (918 kg)
Engine:Yamaha F60
Fuel Capacity34 gal
Max Speed, 1/2 load:22 knots
Cruising Speed:13-17 knots
Range at Cruising Speed:170 nm
Potable Water:30 gal
Ballast Tank Capacity:76 gal (652# s.w.)

 

Construction Details

Shearwater’s major structure was built on laser cut MDF and plywood molds by David Sutter on Bainbridge Island. The boat was finished out in my shop in Seattle.

The hull topsides are 14mm  western red cedar strip planking, and the hull bottom is one layer of 6mm Sapele ply sandwiched between two 4mm layers of Oukoume. Chine logs and stem are Alaska yellow cedar. The hull is sheathed with three layers of glass and one layer of kevlar.  Interior structure, cabin and decks are 1/2” Divinycel foam core with either carbon or glass skins.

Post-cured Pro-Set epoxy laminating resin was used throughout, and West System for the secondary bonding.

The fantastic paint job is by Diamond Painting in Seattle.