Slingshot 16 Trimaran Plans

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15' 10"/4.826 m
Available for download now


This is an instant download for full plans. For free study plans, click HERE.


  • Top Speed (typical) = 14 mph
  • # Of Occupants = One 
  • Length Overall = 15' 10"
  • Beam Overall = 12' (or 7' folded. For details about folding options, please email me.)
  • Main Hull Beam = 24"
  • Length Of Amas (outriggers / floats) = 14'
  • Weight Of Main Hull (built with 3mm lauan ply) = 75 lbs (34 kg)
  • Weight Fully Rigged = approx. 175 lbs
  • Draft Fully Loaded = 5" max
  • Sail Area = 85 sq ft to 128 sq ft, depending on choice of sail rig.
  • Sail Rig Type = leg o-mutton with boom (or full sloop rig).
  • Mast = aluminum tubing, unstayed (or optionally stayed rig).
  • And you get FREE EMAIL SUPPORT for your build - no matter how long it takes!

Slingshot 16 Trimaran With Optional 118 Sq. Ft. Radial Batten Sail

If you're looking for a quick little boat that's comfortable, nimble, ultra-stable, super-fast to rig, gets you sailing in just 10 minutes, and will run circles around most other sailboats - you have just found it!

The "Slingshot 16" trimaran will hit 14 mph, points higher than 45 degrees, and turns on a dime - all while you sit comfortably in your seat, facing forward, with both hands free thanks to foot-pedal steering. She can be launched in 4" of water and sailed away - upwind - in just 6".

Many of the Slingshot 16's benefits over "simpler" hull designs are the result of its hydrodynamically superior 5-panel hull with a flat-bottom center panel, which planes much more easily than 3- or 4-panel hulls.

Laura’s Boat - The original inspiration for Slingshot 16

Over the years, quite a few of the folks who have visited my web site ( have requested plans, and most of the requests have been for the small tri known as"Laura's Boat," which I originally built for my dear wife back in 2010.

The "Slingshot 16" I now offer plans for is based on Laura's Boat, but it has 2" more freeboard, a fuller bow, amas that are longer by 2', and is has been beefed up where it matters to safely carry more sail. In fact, I have had as much as 128 sq ft of sail on it, which is quite a bit for an unstayed mast - i.e., no shrouds. I think 110 sq ft of sail is probably the ideal "maximum" for general day-sailing. (Though we sailed the original Laura's Boat for years with just an 85 sq ft sail, and Laura still prefers that very simple rig.)

And if you'd like to see just how nimble and quick the Slingshot 16 really is, here's a short video of the Slingshot 16 going 10-13 mph, and another short video demonstrating the joys of hands-free tacking - changing direction a full 180 degrees without touching anything but the steering foot pedals:


All of the improvements made to the Slingshot 16 over the original Laura's Boat add about 10 lbs, but also make for a much sturdier and more seaworthy boat. The 3" splash-guard overhang around the edges of the foredeck make an already-dry boat even drier to sail, and the longer amas enhance both speed and smoothness of ride.

Over the years, I have let other folks take out Laura's Boat I when I took out my own 16' boat. Not only did they "get the hang of it" within the first 15 minutes, but it was all but impossible to get them back out of the boat! Seriously, I had to chase them down (not an easy thing) and tell them we needed to call it a day. They said it was like 'a Go-Kart on the water."

Although I have 4 trimarans ready to sail (two 16-footers, and 19-footer, and a 24-footer), it's the Slingshot 16 that I always seem to grab when the urge to sail hits me. Although all these little tris are quick, nimble, dry, stable, and a blast to sail, Slingshot 16 just seems to put it all together in the most irresistible way.

Plywood List:

NOTE: Both the original Laura's Boat (6 years old and going strong as of 2016) and my Slingshot 16 were built from 3mm lauan "doorskin" ply costing about $12 a sheet, and from 6mm ply costing about $22 a sheet. Or, you can spend the extra $ for okoume or some other pricey species of plywood. As long as the glue is waterproof, you can use any ply you wish.

Main Hull 2 sheets of 3mm ply, one sheet of 6mm ply (decks).

Amas (outriggers): 2 sheets of 3mm ply, one sheet of 6mm ply (tops).

Plans Include:

  • An extremely detailed construction manual including more than 280 photos detailing the complete building process, with over 70,000 words of explanatory text by Frank Smoot.
  • A separate drawings manual with dozens of superbly detailed, multicolor CAD drawings by Jerome Delaunay showing every construction detail with crystal clarity.
  • PLUS - I am always here at to provide whatever email support you may need!


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Additional Information

Designer Name:
Frank Smoot
Sail area (Imperial / Metric):
85 sq ft / 7.9 sq. m to 128 sq. ft / 11.9 sq. m
Rig Type:
Leg O' mutton, Sloop
Ballast Weight:
Keel Type:
Length (range):
8' - 15'11"' / 2.44m - 4.85m
15' 10"/4.826 m
Length at Waterline:
15' 10"/4.826 m
12'/3.66m (or 7'/2.13m folded)
Hull Weight:
85 - 199 lbs / 38.56 - 90.27kg
Estimated Hull Weight:
175 lbs/79.3787kg
Under 6" / 15.24cm
Unloaded Draft:
Primary Material:
Marine Plywood
Method of Construction:
Stitch and Glue
Hull Type:
Hull Shape:
Power Source:
Human, Wind
Horsepower Rating:
Built-in Floatation:
Unit of Measure:
Instruction Manual:
Step-by-Step Instructions
Lofting Required:
Recommended Experience Level:
Designer's Thoughts on Experience Level:
Chuck Leinweber's suggestion
Boat Type:
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