The Atlantic is well-powered with enough sail area to move in light air, with acceptable motion comfort for coastal passages.
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 21.5′, the Atlantic tops out around 6.2 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √21.5′ LWL = 6.2 kts
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
21.9
Powerful cruiser/racer — quick in light air, reef early when it pipes up.
Ballast / Displacement
62.2%
Race-oriented ballast ratio — very stiff and powerful.
Displacement / Length
205
Moderate — a good balance of speed and load-carrying ability.
Comfort Ratio
23.9
Acceptable coastal comfort — fine for weekends, notice the chop offshore.
Capsize Screening
1.57
Below the 2.0 offshore threshold — acceptable for ocean passages.
Pounds/Inch Immersion
559lbs
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
23.9
Acceptable coastal comfort — fine for weekends, notice the chop offshore.
Under 20 — Snappy, racing motion
20–30 — Acceptable coastal
30–40 — Good offshore comfort
Over 40 — Very comfortable offshore
Capsize Screening Formula
1.57
Below the 2.0 offshore threshold — acceptable for ocean passages.
Under 2.0 — Acceptable for offshore
Over 2.0 — Coastal / protected waters
PHRF Fleet Position
Where the Atlantic sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Cruiser/Racer 90–150
Cruiser 150–210
Heavy Cruiser 210–300
Lightning
153s/nm
Shields
176s/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° |
2.8 |
3.6 |
4.0 |
4.2 |
| Close Reach60° |
3.4 |
4.3 |
4.8 |
5.0 |
| Beam Reach90° |
4.2 |
5.3 |
5.9 |
6.2 |
| Broad Reach120–135° |
3.9 |
4.9 |
5.5 |
5.7 |
| Run150–180° |
3.1 |
3.9 |
4.4 |
4.6 |
These are simplified estimates based on hull speed (6.2 kts),
SA/D (21.9), 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 Atlantic — based on sail area, ballast, and displacement characteristics.
Ghost
Sweet Spot
Reef
Heavy
0–6 kts
6–20 kts
20–30 kts
30+ kts
Ghosting
0–6 kts
Light air, motor-sailing likely. Need patience and a light genoa.
Sweet Spot
6–20 kts
Comfortable under full sail. Best speed-to-comfort ratio.
Time to Reef
20–30 kts
Time to shorten sail. Reef the main, swap to a working jib.
Heavy Weather
30+ 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 Atlantic.
|
Atlantic |
Lightning |
Shields |
| Dimensions |
| LOA |
30.5 |
19.0 |
30.2 |
| LWL |
21.5 |
15.3 |
20.0 |
| Beam |
6.5 |
6.5 |
6.4 |
| Displacement |
4,559 |
700 |
4 |
| Ballast |
2,835 |
130 |
3 |
| Sail Area |
377 |
172 |
360 |
| Performance |
| PHRF |
— |
153 |
176 |
| SA/Disp |
21.9 |
35.0 |
20.9 |
| Bal/Disp |
62.2 |
18.6 |
67.0 |
| Comfort |
23.9 |
5.5 |
25.9 |
| Capsize |
1.57 |
2.93 |
1.55 |
| Hull Speed |
6.2 |
5.2 |
6.0 |