i550 by Watershed Sailboats

Annoyingly fast sport boat

Length overall18'5.5 m
Beam8'2.45 m
Draft4' 7"1.4 m
Ballast weight165 lbs75 kg
Displacement772 lbs350 kg
Sail area237 sq. ft.22.00 m2
Spi area355 sq. ft.33.00 m2
Hull construction Stich-n-glue
See also Sport Boat 18

URL: http://www.i550sportboat.com/


The i550 is easy to construct, even for even the amateur builder, with a plywood "stitch-and-glue" method that ensures a light, solid hull, and a quick build. Or, to save drawing and cutting time, you can buy a kit from us, cut from the master templates or full-size paper patterns that are very accurate.

The i550 is annoyingly fast and has troubled much larger sportboats, like Elliot 7’s and a Melges 24.

The first i550 was launched in Australia a few years ago, home built by Andrew Clauson. It is the fabled Tokyo Trash Baby of YouTube fame.

The i550 is a big winner in the bang for the buck department. You’ll not only have the satisfaction of crafting your own sportboat, but think of the $25 or $35 thousand dollars you’ll be saving. Resourceful scavengers can put one together for $6,000 or less (US). Double that and you’ll have a carbon spar, fine sails, nice foils by a skilled maker and new everything. The building time typically spent comes in at about 400 hours for the hull, keel and rudder.

Following the plan set page by page, with the parts diagrams and instructions, the boat will come out right.

The rig has height and length limits, but the layout of the deck and cockpit are open to interpretation. Construction is simple stitch and glue plywood, epoxy and glass. Two people can have the hull looking like a hull in a weekend.

Put in the transom and bulkheads next while it is right side up. Epoxy coat and glass tape the parts in place and roll it over. Fair the bottom and fiberglass cloth it. There is room down below for simple camping style. Plenty of room on deck gives you room to move around. The lifting bulb keel gives stability and righting moment, but, most importantly, lets the boat launch easily at any boat ramp.

The plan’s pack consists of construction notes, suggested bill of materials, profile, plan and section views, nesting diagram, hull panel diagrams, frame diagrams, interior diagrams, keel and keelbox diagram, rudder diagram, cabin trunk diagram, deck layout and a rigging diagram. The plans pack is in a notebook-ring binder. Plans include both the standard and the extended cockpit version. Some creative builders are even building flush deck versions, and the Portland Group, who formed the North American Class (NA.org) have perfected the rounded flush deck version.

The mast can be obtained through a number of sources (both aluminum and carbon fiber). We will soon be offering keel bulbs and keels, ballast bulb molds and rudders. We also will build the i550 for you to any stage of completion. Clubs are especially encouraged to inquire. Before and after any purchase, Also, we are always here to answer your questions, anytime by email or phone. Five are now sailing in Australia. Many other builders, who have bought kits or full sized paper plans, are making great progress and we expect those i550s to start launching soon.


See also

Design Length Beam Sail area Engine power Compare
Sport Boat 18 Sport Boat 18 by Bateau.com
[SB18] A trailerable high performance sail boat with lifting keel
5.5 m
2.44 m
241 sq. ft.
22.40 m2
2 - 4

Boats about same size as i550

Swaggie   Swaggie
A mighty, miniature long range cruiser

LOA: 18'/5.5 m   compare
Sport Boat 18   Sport Boat 18
[SB18] A trailerable high performance sail boat with lifting keel

LOA: 18'/5.5 m   compare
Vagabond 18   Vagabond 18
[VG18] A fast day sailor with cabin

LOA: 18' 2"/5.54 m   compare
Daysailer/Pocket Cruiser

LOA: 19' 6"/5.94 m   compare

Questions? Suggestions? Contact us at: info@boatplans.cc