Sonic 23
Sonic Sailboats Limited · designed by Joseph D'Alessio · 1981
fin keelMasthead sloopCanada
The Sonic 23 is a 23-foot masthead sloop sailboat designed by Joseph D'Alessio and built by Sonic Sailboats Limited, first launched in 1981.
General
| Builder | Sonic Sailboats Limited |
|---|---|
| Designer | Joseph D'Alessio |
| Years built | 1981 |
| Hull type | fin keel |
| Rig type | Masthead sloop |
| Construction | — |
| Origin | Canada |
Dimensions
| LOA | 23.00 ft7.01 m |
|---|---|
| LWL | 20.00 ft6.10 m |
| Beam | 7.58 ft2.31 m |
| Draft (max) | 3.75 ft1.14 m |
| Displacement | 3,400 lb1,542 kg |
| Ballast | 1,500 lb680 kg |
| Sail Area | 242 ft²22.5 m² |
Design ratios
Computed from the specs above using the standard formulas. Try the sailboat calculators with your own numbers.
SA / Displacement 17.12 Cruiser — good all-round performance
Ballast / Displacement 44.1 % Higher = stiffer / more sail-carrying power
Displacement / Length 190 Light
Comfort Ratio 16.9 Racing / light coastal
Capsize Screening 2.02 Better suited to coastal use (> 2.0)
Hull Speed 6.0 kn Theoretical max displacement speed
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.
