The Cork 1720 is aggressively canvassed for its weight, with a quick, snappy motion best suited to day sailing, and respectable in club racing.
Hull Speed
The theoretical displacement-mode speed limit — determined by waterline length, not engine or sail power.
A displacement hull pushes a bow wave whose speed is limited by the waterline length.
With a waterline of 23.3′, the Cork 1720 tops out around 6.5 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √23.3′ LWL = 6.5 kts
Performance Ratios
Racing handicap, sail-carrying power, stability and comfort — and what each one actually tells you about a day on the water.
PHRF Rating
96s/nm
Cruiser/racer — competitive in club racing, comfortable cruising.
SA / Displacement
27.6
Performance-oriented — carries a lot of canvas for its weight.
Ballast / Displacement
46.3%
Race-oriented ballast ratio — very stiff and powerful.
Displacement / Length
106
Ultralight — responsive and fast, but carries less stores.
Comfort Ratio
11.7
Quick, snappy motion — better for day sails and racing than long passages.
Capsize Screening
2.27
Above the 2.0 offshore threshold — best suited for coastal and protected waters.
SA/Disp (Calculated)
29.0
Computed from measured I/J/P/E rather than reported sail area.
Pounds/Inch Immersion
680lbs
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
11.7
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
2.27
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
PHRF Fleet Position
Where the Cork 1720 sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Racer 0–90
Cruiser/Racer 90–150
Cruiser 150–210
Cork 1720
96s/nm
Cruiser/racer — competitive in club racing, comfortable cruising.
J/80
129s/nm
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° |
3.0 |
3.9 |
4.3 |
4.5 |
| Close Reach60° |
3.7 |
4.7 |
5.2 |
5.4 |
| Beam Reach90° |
4.5 |
5.7 |
6.4 |
6.9 |
| Broad Reach120–135° |
4.2 |
5.3 |
5.9 |
6.4 |
| Run150–180° |
3.3 |
4.2 |
4.7 |
4.9 |
These are simplified estimates based on hull speed (6.5 kts),
SA/D (27.6), 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 Cork 1720 — based on sail area, ballast, and displacement characteristics.
Ghost
Sweet Spot
Reef
Heavy
0–5 kts
5–18 kts
18–28 kts
28+ kts
Ghosting
0–5 kts
Light air, motor-sailing likely. Need patience and a light genoa.
Sweet Spot
5–18 kts
Comfortable under full sail. Best speed-to-comfort ratio.
Time to Reef
18–28 kts
Time to shorten sail. Reef the main, swap to a working jib.
Heavy Weather
28+ 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 Cork 1720.
|
Cork 1720 |
Firebird |
First 26 Beneteau |
J/80 |
Sonata 26 |
Twister 800 |
| Dimensions |
| LOA |
26.3 |
26.3 |
26.3 |
26.3 |
26.3 |
26.3 |
| LWL |
23.3 |
25.0 |
22.9 |
22.8 |
19.8 |
25.6 |
| Beam |
8.2 |
17.3 |
9.2 |
9.4 |
8.2 |
8.9 |
| Displacement |
3 |
1 |
4 |
3 |
2 |
4 |
| Ballast |
1 |
— |
1 |
1 |
500 |
1 |
| Sail Area |
358 |
382 |
291 |
338 |
277 |
333 |
| Performance |
| PHRF |
96 |
— |
— |
129 |
— |
— |
| SA/Disp |
27.6 |
61.2 |
16.4 |
24.8 |
22.3 |
18.7 |
| Bal/Disp |
46.3 |
— |
30.2 |
42.7 |
— |
— |
| Comfort |
11.7 |
— |
16.2 |
17.9 |
12.2 |
15.9 |
| Capsize |
2.27 |
— |
2.18 |
1.80 |
2.32 |
2.10 |
| Hull Speed |
6.5 |
— |
6.4 |
6.9 |
6.0 |
6.8 |