Almaguin 400

The Almaguin 400 is a versatile 4-metre utility runabout, designed with cottagers, anglers and day trippers in mind. When heavily loaded (190 kg “official rated” capacity), it is a versatile working boat, capable of hauling heaps of crew and gear on inland lakes and rivers. After offloading the cargo and surplus crew, and opening the throttle, the Almaguins act more like racing hulls- capable of towing waterskiers and pushing 30-knot speeds in flat water. (Being high-sided, they present too much windage to keep up with real racing hulls in calm water.) They are built in taped-seam plywood, and do not require elaborate jigs or high-precision carpentry.

Almaguin 400 & 500 utility runabouts

The design was inspired by Phil Bolger's Diablo, a simple, practical and well-performing boat that has served me well for many years. The Almaguin is designed to offer similar performance and carrying ability to the Diablo, with a drier and more comfortable ride in rough conditions. The construction methods used for this boat will be familiar to anyone who has worked with stitch-and-glue construction or the “tack and tape” models from Bolger's “instant boat” series. Unlike typical stitch-and-glue construction, the panels of these boats are not stitched together with wire; they are tacked to the bulkheads one by one as the hull is assembled. The structural bulkheads form the only building jig required, and remain a part of the finished boat.

The Almaguin hull is of a double-V configuration; it can also be thought of as a deep-V with a shallow-V pad. When lightly loaded at rest, the Almaguins will feel a bit tippy, and will roll 10 degrees or so as people move around and get in and out (they are, however, very hard to roll past this angle). As they are loaded down, the outer chines become immersed, and the roll will diminish. The entry is relatively sharp, there is more freeboard than usual for boats this size, and the motor well presents an effectively full-height transom to a following sea; thus, the Almaguin should be somewhat drier and more comfortable in heavy conditions than a typical aluminum skiff of comparable dimensions.

As the hull accelerates to planing speeds, both the inner 7-degree V and the outer 26.5-degree V will act as planing surfaces; the net effect is performance at low planing speeds that is comparable to what you would get from an ordinary 15-degree deep V hull. There will be a noticeable planing hump as the boat climbs over its bow wave. If the Almaguin is lightly loaded, the water will begin to break away from the inner chine as the hull accelerates. The boat is now running on the relatively narrow 7-degree V, with a considerable improvement in top speed; the outer V now serves as a raceboat style anti-trip chine. In turns, she will bank inward and ride on the outer V.

The Almaguin 400 is just about the largest boat that can be comfortably car-topped (although a trailer is preferable), and it'll fit (barely) in the bed of a full-size pickup with the tailgate down. Appropriate engines are 20” shaft outboards from 7 to 30 hp (20 hp if tiller steered), the middle of that range being generally ideal.

A first-time builder assembling the boat in his spare time should allow four to eight months for the build; an experienced, motivated builder familiar with taped-seam construction will likely find that she can produce an Almaguin hull in seven to ten working days, possibly less.

The Almaguins can be built with many different interior layouts. Some possible suggestions are included in the build instructions, but the final layout is up to the builder's discretion (subject to certain structural limitations regarding cut-down bulkheads, detailed further in the plans).

Notes to Builders

Fine carpentry skills are not required. A potential builder should already be familiar with standard power tools (circular saw, band saw, drill, etc.), should be able to accurately measure and mark co-ordinates on a flat sheet, and should either have experience with taped-seam construction, or read up on the method through books and builders' articles.

I do not offer full-size Mylar patterns, as some commerical plan houses do. You are welcome to print the DWF6/DWFx drawings at 1:1 scale if you so choose, but I believe that full-size patterns are not worth the cost for a boat like this. Lofting the panels onto the plywood is neither difficult nor complicated- as long as you can use a tape, square, pencil and batten, you should have few difficulties lofting the panel layouts by hand.

The build instructions manual can be viewed here: Almaguin build instructions (340kB PDF).


The plan set for each of the Almaguins consists of five C-size (18 x 24 inch) pages and a ten-page build instructions booklet. The plans consist of:

  1. General arrangement, profiles and body plan
  2. Layout drawings for bulkheads, stem and miscellaneous parts
  3. Layout drawings for inner and outer V panels and chines
  4. Layout drawings for side panels, and assembly sequence
  5. Construction details

The drawings are prepared in SI units for North American standard material sizes. Standard scales of 1:1, 1:10 and 1:15 are used, although it should not be necessary to scale dimensions off the plans. Metric-standard plywood (125 x 250) can also be used with no changes to the plans.

It's cheaper for you, and more environmentally friendly, to have the drawings printed at a local shop instead of paying a courier to transport a roll of paper. The plans are distributed as PDF files, and if desired, you can also receive a copy in DWF6 or DWFx ePlot formats at no extra cost.

A set of plans for the Almaguin 400 includes PDF (and DWF6/DWFx if desired) copies of the plans, the right to build one boat from the plans, and as much technical support (via electronic communication) as you need to finish your boat. There are no shipping costs, and any applicable taxes are included. If you don't have a local print shop, I can arrange for printed copies to be couriered to you (at cost).

Please contact me for further details if you are interested in either of these boats.

Length overall: 

4 m

Length waterline: 

3 m

Displacement light-ship: 

100 kg

Displacement at design load: 

480 kg

Beam overall: 

1 m

Draught normal: 

1 m

Draught minimum: 

0 m

Wetted surface: 

2 m²

Power typical: 

10 kW

Power description: 

Outboard 7 to 20 hp (up to 30 hp with remote steering)



Bottom loading: 

190 kg/m²

Plans available: 


Plans cost: 

$50 CAD

Build status: 

Model tests complete. Two hulls currently in build.

Design number: