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Performance

Geary 18 Performance

How the Geary 18 performs on the water — racing handicap, sail-carrying power, stability and comfort.

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The Geary 18 is aggressively canvassed for its weight, with a quick, snappy motion best suited to day sailing.

Hull Speed

The theoretical displacement-mode speed limit — determined by waterline length, not engine or sail power.

5.3 kts
A displacement hull pushes a bow wave whose speed is limited by the waterline length.

Performance Ratios

Racing handicap, sail-carrying power, stability and comfort — and what each one actually tells you about a day on the water.

SA / Displacement
49.2
Performance-oriented — carries a lot of canvas for its weight.
Displacement / Length
64
Ultralight — responsive and fast, but carries less stores.
Comfort Ratio
5.2
Quick, snappy motion — better for day sails and racing than long passages.
Capsize Screening
2.71
Above the 2.0 offshore threshold — best suited for coastal and protected waters.
Hull Speed
5.3kts
Pounds/Inch Immersion
2lbs
Weight needed to sink the hull one inch — loading sensitivity.

Motion & Offshore Suitability

Two ratios that matter most when you're planning passages — how the boat feels in a seaway, and whether the hull geometry is suitable for open ocean.

Comfort Ratio
5.2
Quick, snappy motion — better for day sails and racing than long passages.
Under 20 — Snappy, racing motion
20–30 — Acceptable coastal
30–40 — Good offshore comfort
Over 40 — Very comfortable offshore
Capsize Screening Formula
2.71
Above the 2.0 offshore threshold — best suited for coastal and protected waters.
Under 2.0 — Acceptable for offshore
Over 2.0 — Coastal / protected waters

Estimated Speed by Wind

Rough boat speed estimates at different true wind speeds and points of sail — derived from hull speed, SA/D, and displacement, not measured polars.

Point of Sail 6 kts TWS 10 kts TWS 15 kts TWS 20 kts TWS
Close-hauled40–50° 2.5 3.1 3.5 3.6
Close Reach60° 3.0 3.8 4.2 4.4
Beam Reach90° 3.7 4.6 5.2 5.6
Broad Reach120–135° 3.4 4.3 4.8 5.2
Run150–180° 2.7 3.4 3.8 4.0
These are simplified estimates based on hull speed (5.3 kts), SA/D (49.2), and empirical efficiency curves — not instrument-measured polars. Real-world speed varies with sea state, bottom condition, sail trim, and current. Speeds in gold approach hull speed; bold gold means near or at hull speed.

Wind Range & Comfort Envelope

Estimated wind ranges for comfortable sailing on the Geary 18 — based on sail area, ballast, and displacement characteristics.

Ghost
Sweet Spot
Reef
Heavy
0–5 kts 5–16 kts 16–24 kts 24+ kts
Ghosting
0–5 kts
Light air, motor-sailing likely. Need patience and a light genoa.
Sweet Spot
5–16 kts
Comfortable under full sail. Best speed-to-comfort ratio.
Time to Reef
16–24 kts
Time to shorten sail. Reef the main, swap to a working jib.
Heavy Weather
24+ kts
Storm conditions. Storm jib or bare poles. Seek shelter if coastal.

How It Compares

Side-by-side with the boats most often cross-shopped against the Geary 18.

Geary 18 Alden O Class Mk Ii Duxbury Duck Goldeneye Herreshoff Marlin 18 Rhodes Rhodes 18
Dimensions
LOA 18.2 18.2 18.0 18.3 18.1 18.0
LWL — 15.4 15.1 15.8 12.3 17.0
Beam 5.5 6.7 6.3 6.3 5.3 6.3
Displacement 525 2 700 2 1 1
Ballast — 550 — 1 430 —
Sail Area 200 192 342 193 — 162
Performance
SA/Disp 49.2 19.4 69.5 16.8 — 25.1
Bal/Disp — 27.5 — 52.8 34.4 —
Comfort 5.2 15.2 5.8 20.0 — 8.2
Capsize 2.71 2.12 2.85 1.87 — 2.46
Hull Speed 5.3 5.3 5.2 5.3 — 5.5