G-Cat 5.7
G-Cat Multihulls · designed by Hans Geissler · 1980
nonecatamaranUnited States
The G-Cat 5.7 is a 19-foot catamaran sailboat designed by Hans Geissler and built by G-Cat Multihulls, first launched in 1980.
General
| Builder | G-Cat Multihulls |
|---|---|
| Designer | Hans Geissler |
| Years built | 1980 |
| Hull type | none |
| Rig type | catamaran |
| Construction | fiberglass |
| Origin | United States |
Dimensions
| LOA | 18.67 ft5.69 m |
|---|---|
| LWL | 17.50 ft5.33 m |
| Beam | 8.00 ft2.44 m |
| Draft (max) | —— |
| Displacement | 360 lb163 kg |
| Ballast | —— |
| Sail Area | 235 ft²21.8 m² |
Design ratios
Computed from the specs above using the standard formulas. Try the sailboat calculators with your own numbers.
SA / Displacement 74.30 Performance / racer — powered up
Displacement / Length 30 Ultralight
Comfort Ratio 2.0 Racing / light coastal
Capsize Screening 4.50 Better suited to coastal use (> 2.0)
Hull Speed 5.6 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
$10,000 typical range $8,000 – $12,000
⚠ 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.
