The Andrews 70 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.
A displacement hull pushes a bow wave whose speed is limited by the waterline length.
With a waterline of 60.0′, the Andrews 70 tops out around 10.4 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √60.0′ LWL = 10.4 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
31.7
Performance-oriented — carries a lot of canvas for its weight.
Ballast / Displacement
45.3%
Race-oriented ballast ratio — very stiff and powerful.
Displacement / Length
54
Ultralight — responsive and fast, but carries less stores.
Comfort Ratio
17.6
Quick, snappy motion — better for day sails and racing than long passages.
Capsize Screening
2.02
Above the 2.0 offshore threshold — best suited for coastal and protected waters.
Pounds/Inch Immersion
19lbs
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
17.6
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
2.02
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° |
4.9 |
6.2 |
6.9 |
7.2 |
| Close Reach60° |
5.9 |
7.5 |
8.4 |
8.7 |
| Beam Reach90° |
7.3 |
9.2 |
10.2 |
11.1 |
| Broad Reach120–135° |
6.7 |
8.5 |
9.5 |
10.3 |
| Run150–180° |
5.4 |
6.8 |
7.6 |
7.9 |
These are simplified estimates based on hull speed (10.4 kts),
SA/D (31.7), 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 Andrews 70 — 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 Andrews 70.
|
Andrews 70 |
Baltic 73 |
Channel 70 |
Santa Cruz 70 |
Swan 68 |
Swan 70 |
| Dimensions |
| LOA |
68.5 |
73.2 |
70.5 |
68.0 |
67.7 |
70.1 |
| LWL |
60.0 |
60.7 |
57.8 |
62.0 |
54.7 |
61.7 |
| Beam |
15.0 |
18.0 |
20.9 |
15.1 |
17.8 |
17.5 |
| Displacement |
26 |
77 |
52 |
24 |
88 |
66 |
| Ballast |
11 |
29 |
19 |
9 |
35 |
23 |
| Sail Area |
1,743 |
2 |
2,571 |
— |
— |
2 |
| Performance |
| SA/Disp |
31.7 |
22.0 |
29.5 |
— |
— |
24.6 |
| Bal/Disp |
45.3 |
38.6 |
36.2 |
40.0 |
40.0 |
36.2 |
| Comfort |
17.6 |
39.3 |
23.0 |
— |
— |
35.2 |
| Capsize |
2.02 |
1.70 |
2.24 |
— |
— |
1.74 |
| Hull Speed |
10.4 |
10.4 |
10.2 |
— |
— |
10.5 |