The Seal 28 is modestly canvassed and unhurried, 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 21.9′, the Seal 28 tops out around 6.3 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √21.9′ LWL = 6.3 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
13.3
Modestly canvassed — a comfortable, unhurried cruiser.
Ballast / Displacement
40.3%
Stiff enough to carry a big genoa comfortably into moderate breeze.
Displacement / Length
306
Moderate-heavy — carries provisions well, deliberate in light air.
Comfort Ratio
22.3
Acceptable coastal comfort — fine for weekends, notice the chop offshore.
Capsize Screening
2.04
Above the 2.0 offshore threshold — best suited for coastal and protected waters.
Pounds/Inch Immersion
769lbs
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
22.3
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
2.04
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 Seal 28 sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Cruiser/Racer 90–150
Cruiser 150–210
Heavy Cruiser 210–300
Aloha 28
195s/nm
Grampian 28
198s/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° |
2.2 |
2.8 |
3.2 |
3.3 |
| Close Reach60° |
2.7 |
3.4 |
3.8 |
4.0 |
| Beam Reach90° |
3.3 |
4.2 |
4.7 |
4.9 |
| Broad Reach120–135° |
3.1 |
3.9 |
4.3 |
4.5 |
| Run150–180° |
2.5 |
3.1 |
3.5 |
3.6 |
These are simplified estimates based on hull speed (6.3 kts),
SA/D (13.3), 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 Seal 28 — based on sail area, ballast, and displacement characteristics.
Ghost
Sweet Spot
Reef
Heavy
0–8 kts
8–24 kts
24–34 kts
34+ kts
Ghosting
0–8 kts
Light air, motor-sailing likely. Need patience and a light genoa.
Sweet Spot
8–24 kts
Comfortable under full sail. Best speed-to-comfort ratio.
Time to Reef
24–34 kts
Time to shorten sail. Reef the main, swap to a working jib.
Heavy Weather
34+ 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 Seal 28.
|
Seal 28 |
Aloha 28 |
Grampian 28 |
Impala 28 Thomas |
Pearson 28 1975 80 |
Southerly 28 |
| Dimensions |
| LOA |
28.0 |
28.0 |
28.0 |
28.0 |
28.0 |
28.0 |
| LWL |
21.9 |
24.5 |
24.5 |
23.2 |
24.0 |
24.0 |
| Beam |
9.8 |
9.4 |
9.5 |
9.3 |
9.3 |
9.0 |
| Displacement |
7 |
6 |
6 |
4 |
7 |
8 |
| Ballast |
2 |
3 |
3 |
— |
3 |
— |
| Sail Area |
310 |
373 |
384 |
335 |
395 |
— |
| Performance |
| PHRF |
— |
195 |
198 |
— |
— |
— |
| SA/Disp |
13.3 |
16.8 |
17.0 |
20.3 |
16.1 |
— |
| Bal/Disp |
40.3 |
44.4 |
44.4 |
— |
45.0 |
— |
| Comfort |
22.3 |
20.6 |
20.8 |
13.9 |
24.9 |
27.9 |
| Capsize |
2.04 |
2.00 |
2.00 |
2.28 |
1.86 |
1.77 |
| Hull Speed |
6.3 |
6.6 |
6.6 |
6.5 |
6.6 |
6.6 |