W17 trimaran

W17  is an open, 17 ft. trimaran designed by Canadian naval architect Mike Waters.  Plans are available to build yourself. Mike Waters has forty years´experience with multihulls, and for many years owned the prototype of Dragongfly 800. The architect designed and built W17 for his own use, but building plans have now sold in more than 150 copies in all parts of the world. Top speed has been measured at 15 knots, and 10 knots is common. The rig is available in two versions - a cruise version with  wood rotating wing-mast and smaller sail area, and a sport version with carbon rotating wing-mast and larger sail area. An extended version (W19) with a cuddy cabin for one person in under construction; plans may be available later.  W19 has a swing arm folding mechanism. Building material for the boats are wood and epoxy.


  • unsinkable with self draining cockpit
  • comfortable and protected sit-in cockpit, as opposed many other small trimarans that are sit-on
  • may be transported on a standard trailer; with flat bottom W17 is effortlessly launched
  • folding; the floats swing upwards and rest on top of the main hull (swing folding where floats fold towards main hull in under development)
  • hull length 5.2 m
  • total beam 4.2 m, folded beam 2.2 m (swing beam version 2.4 m)
  • pivoting daggerboard in main hull
  • swivel blade rudder in main hull
  • net weight 185 kg
  • cruise version has epoxy/plywood rotating wing-mast 7.35 m 
  • cruise version sail area: main sail 11.1 m2, jib 4.4 m2, downwind sail 9.6 m2
  • race version has carbon rotating wing-mast 8.0  m
  • race version sail area: main sal 13.7 m2, jib 4.9 m2, downwind sail 10.5 m2
  • material costs are in the range of € 7-8000 with wood wing-mast; building time 350-600 hours; add € 1500 in materials for carbon rotating wing-mast
Download article about W17
Buy building plans

Small Trimaran Design website

Mike Waters´website is an excellent source of information about small trimarans:

  • presentation of W17 og W22
  • photo and video
  • published articles
  • Information about design and building
  • sailing tips
  • review of other small trimarans
  • etc.


W17 sailing
folded on trailer

W19

W19 is an extended W17 with fixed windscreen and a single berth. W19 has swing arm folding; is 6 m long and weighs 340 kg.

Slideshow with details