Saturday, October 1, 2011

A 20 foot (6 meter) outrigger sailing canoe

Andy Wong's double outrigger with custom amas.

Length  =  20 ft (6.0 Meters)
Beam of main hull = 20 1/2" (520mm)
Beam overall (single outrigger) = 9' 2" (2800mm)
Beam overall (double outrigger) = 12' 6" (3800mm)
Sail area = 80 sq Ft  (7.5 Sq M)

The Tamanu is a "three board" canoe with a flat bottom and moderate  rocker.  The hull can be quickly and easily constructed with 1/4" or 3/16" plywood.   The ama or amas can be foam and fiberglass or hollow plywood.

The most important difference between the Tamanu and my other designs is the self bailing footwells.  The hull is completely decked over with self bailing footwells or a larger self bailing cockpit making it suitable for more ambitious cruising.  The Tamanu can be configured with a single outrigger, double outrigger, or as a catamaran.

Jon Gardner's Tamanu in Hawaii
Hjalmar Turesson's Tamanu
My own Tamanu in Fiji with a sprit rig
Tamanu with open non self bailing midsection.

The rig style is tacking only and a kick-up rudder is mounted on the stern or on the side.  A pivoting leeboard is mounted on the side of the hull.  There are two rig options shown in the plans; the first can be reefed by rolling the sail around the windsurf mast.  The second option uses a stub mast that is used to raise and lower the yard and sail.  However, Tamanus have successfully used lug rigs, junk rigs, sprit rigs, gaff rigs and windsurf rigs.

While my other designs are cartoppable, the Tamanu is almost too large and heavy to be transported on a car roof.  Heavier racks on a pickup truck or a trailer is recommended.

The Tamanu was chosen to be used in the Eco Challenge in Fiji 2019.  73 copies were built.
Some Tamanus are doubled up into catamarans.  This one has a shunting rig.