Polly Wog: A Free Plan for a Fast 11 ft 6 in Plywood Boat
William D. Jackson's convex-bottom planing boat hit 34 mph on a Mercury 10 and takes 5 to 20 hp outboards.
Polly Wog looks like a modest little utility boat, but its bottom tells a different story. William D. Jackson gave the 11 ft 6 in (3.5 m) hull a convex planing surface, and on a Mercury 10 it reached 34 mph. It carries four people in smooth water and two when it gets rough. That makes it a lively runabout for fishing trips and quick hops across the lake.
Polly Wog at a glance
| Detail | Polly Wog |
|---|---|
| Type | Utility boat |
| Length | 11 ft 6 in (3.51 m) |
| Beam | 56 in (1.42 m) |
| Capacity | 4 persons (smooth water), 2 (rough water) |
| Construction | 1/4 in. plywood over a longitudinally stressed frame; convex planing bottom |
| Power | 5 to 20 hp outboard; 34 mph with a Mercury 10 |
| Designer | William D. Jackson |
| First published | Boat Builder's Handbook, p. 117 |
| Craft Print | No. 152 |
| Plan sheets | 5 |
What makes it quick
The convex planing bottom is the secret: it lets the hull lift and run cleanly once it gets up to speed. Quarter-inch plywood over a longitudinally stressed frame keeps the structure light and stiff at the same time. The result is a hull that stays stiff without carrying extra weight.
The 56 in beam is generous for an 11 ft 6 in boat, so it feels steady at rest. With outboards from 5 to 20 hp, you can choose between economical cruising and real pace. It is a lot of performance for a boat that still fits in a small garage.
The original plan sheets
These are the 5 original sheets, scanned from the magazine. For building, use the full-size PDF in the download section below.
Who designed it
William D. Jackson drew Polly Wog for the Boat Builder's Handbook, page 117, and it was issued as Craft Print No. 152. Few designers contributed as many home-build plans to the Science and Mechanics series as Jackson.
Before you build
- Keep the outboard within the 5 to 20 hp range; more power will not suit an 11 ft 6 in hull built this light.
- Take the capacity ratings seriously: four in smooth water, but only two when it is rough.
- Fair the convex bottom carefully, as bumps and hollows in a planing surface cost speed and spoil handling.
Download the plan
All five original Polly Wog sheets in one file, ready to print at full size or open on a tablet.
Download the complete plan (PDF, 5 sheets, 3.6 MB)
Tools for this
Comments
No comments yet. Be the first to say what you think of this post.