SB20
White Formula · designed by Tony Castro · 2002
keelboatUnited Kingdom
The SB20 is a 20-foot sailboat designed by Tony Castro and built by White Formula, first launched in 2002.
General
| Builder | White Formula |
|---|---|
| Designer | Tony Castro |
| Years built | 2002 |
| Hull type | keelboat |
| Rig type | — |
| Construction | fiberglass |
| Origin | United Kingdom |
Dimensions
| LOA | 20.34 ft6.20 m |
|---|---|
| LWL | —— |
| Beam | 6.89 ft2.10 m |
| Draft (max) | 4.92 ft1.50 m |
| Displacement | 1,510 lb685 kg |
| Ballast | 721 lb327 kg |
| Sail Area | 294 ft²27.3 m² |
Design ratios
Computed from the specs above using the standard formulas. Try the sailboat calculators with your own numbers.
SA / Displacement 35.74 Performance / racer — powered up
Ballast / Displacement 47.7 % Higher = stiffer / more sail-carrying power
Capsize Screening 2.40 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
$15,000 typical range $12,000 – $18,000
⚠ 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.
