The Seamaster 46 is moderately powered for comfortable coastal cruising, with a steady, comfortable ride offshore.
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 40.0′, the Seamaster 46 tops out around 8.5 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √40.0′ LWL = 8.5 kts
Performance Ratios
Racing handicap, sail-carrying power, stability and comfort — and what each one actually tells you about a day on the water.
SA / Displacement
15.3
Moderate sail power — a capable coastal cruiser, not overpowered.
Ballast / Displacement
40.0%
Stiff enough to carry a big genoa comfortably into moderate breeze.
Displacement / Length
230
Moderate — a good balance of speed and load-carrying ability.
Comfort Ratio
35.5
Good offshore comfort — steady enough for multi-day passages.
Capsize Screening
1.78
Below the 2.0 offshore threshold — acceptable for ocean passages.
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
35.5
Good offshore comfort — steady enough for multi-day passages.
Under 20 — Snappy, racing motion
20–30 — Acceptable coastal
30–40 — Good offshore comfort
Over 40 — Very comfortable offshore
Capsize Screening Formula
1.78
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 Seamaster 46 sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Racer 0–90
Cruiser/Racer 90–150
Cruiser 150–210
Tartan 4600
75s/nm
Cambria 44
90s/nm
Oyster 46
135s/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° |
3.2 |
4.1 |
4.5 |
4.7 |
| Close Reach60° |
3.9 |
4.9 |
5.5 |
5.7 |
| Beam Reach90° |
4.8 |
6.0 |
6.7 |
7.0 |
| Broad Reach120–135° |
4.4 |
5.6 |
6.2 |
6.5 |
| Run150–180° |
3.5 |
4.5 |
5.0 |
5.2 |
These are simplified estimates based on hull speed (8.5 kts),
SA/D (15.3), 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 Seamaster 46 — based on sail area, ballast, and displacement characteristics.
Ghost
Sweet Spot
Reef
Heavy
0–7 kts
7–22 kts
22–32 kts
32+ kts
Ghosting
0–7 kts
Light air, motor-sailing likely. Need patience and a light genoa.
Sweet Spot
7–22 kts
Comfortable under full sail. Best speed-to-comfort ratio.
Time to Reef
22–32 kts
Time to shorten sail. Reef the main, swap to a working jib.
Heavy Weather
32+ 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 Seamaster 46.
|
Seamaster 46 |
Cambria 44 |
Kelly Peterson 46 |
Oceanic 46 Brewer |
Oyster 46 |
Tartan 4600 |
| Dimensions |
| LOA |
46.0 |
45.9 |
46.3 |
45.8 |
46.0 |
46.2 |
| LWL |
40.0 |
36.3 |
40.8 |
36.5 |
39.6 |
39.6 |
| Beam |
14.3 |
13.5 |
13.3 |
13.5 |
14.0 |
14.3 |
| Displacement |
33 |
28 |
33 |
33 |
31 |
28 |
| Ballast |
13 |
11 |
11 |
11 |
12 |
8 |
| Sail Area |
982 |
953 |
1 |
— |
980 |
— |
| Performance |
| PHRF |
— |
90 |
— |
— |
135 |
75 |
| SA/Disp |
15.3 |
16.4 |
17.1 |
— |
15.6 |
— |
| Bal/Disp |
40.0 |
40.2 |
— |
34.3 |
40.3 |
30.4 |
| Comfort |
35.5 |
35.3 |
38.5 |
— |
35.4 |
— |
| Capsize |
1.78 |
1.77 |
1.66 |
— |
1.77 |
— |
| Hull Speed |
8.5 |
8.1 |
8.6 |
— |
8.4 |
— |