Impulse
Tim Wilson Yacht Design · designed by Arthur Caldwell · 1975
centreboardcatboat rigAustralia
The Impulse is a 13-foot catboat rig sailboat designed by Arthur Caldwell and built by Tim Wilson Yacht Design, first launched in 1975.
General
| Builder | Tim Wilson Yacht Design |
|---|---|
| Designer | Arthur Caldwell |
| Years built | 1975 |
| Hull type | centreboard |
| Rig type | catboat rig |
| Construction | — |
| Origin | Australia |
Dimensions
| LOA | 13.12 ft4.00 m |
|---|---|
| LWL | —— |
| Beam | 4.94 ft1.51 m |
| Draft (max) | 2.00 ft0.61 m |
| Displacement | 104 lb47 kg |
| Ballast | —— |
| Sail Area | 83 ft²7.7 m² |
Design ratios
Computed from the specs above using the standard formulas. Try the sailboat calculators with your own numbers.
SA / Displacement 60.05 Performance / racer — powered up
Capsize Screening 4.20 Better suited to coastal use (> 2.0)
How these numbers are calculated
- SA / Displacement
SA ÷ (Disp ÷ 64)^(2/3)— Power-to-weight. < 16 under-canvassed, 16–20 cruiser, > 20 racer.- Ballast / Displacement
Ballast ÷ Disp × 100— Stability/stiffness. Higher carries sail better.- Displacement / Length
Disp(lt) ÷ (0.01 · LWL)³— < 100 ultralight, 100–200 light, 200–300 moderate, > 300 heavy.- Comfort Ratio (Brewer)
Disp ÷ (0.65 · (0.7·LWL + 0.3·LOA) · Beam^1.33)— Motion in a seaway. Higher = more comfortable offshore.- Capsize Screening
Beam ÷ (Disp ÷ 64)^(1/3)— ≤ 2.0 favored for offshore; > 2.0 better for coastal use.- Hull Speed
1.34 · √LWL— Theoretical max displacement speed in knots.
Estimated price
$4,500 typical range $3,500 – $5,500
⚠ Rough estimate only — not market data. Derived from a simple model based on length and hull age; actual asking prices vary widely with condition, equipment, engine hours and location.
