The Sigma 38 Ss is moderately powered for comfortable coastal cruising, with a gentle bluewater motion.
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 27.5′, the Sigma 38 Ss tops out around 7.0 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √27.5′ LWL = 7.0 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
14.9
Moderate sail power — a capable coastal cruiser, not overpowered.
Comfort Ratio
43.1
Very comfortable in a seaway — a genuine bluewater motion.
Capsize Screening
1.54
Below the 2.0 offshore threshold — acceptable for ocean passages.
Pounds/Inch Immersion
1lbs
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
43.1
Very comfortable in a seaway — a genuine bluewater motion.
Under 20 — Snappy, racing motion
20–30 — Acceptable coastal
30–40 — Good offshore comfort
Over 40 — Very comfortable offshore
Capsize Screening Formula
1.54
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 Sigma 38 Ss sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Racer 0–90
Cruiser/Racer 90–150
Cruiser 150–210
Yankee 38
120s/nm
Swan 38 Ss
122s/nm
Pearson 385
180s/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° |
2.6 |
3.3 |
3.7 |
3.9 |
| Close Reach60° |
3.2 |
4.0 |
4.5 |
4.7 |
| Beam Reach90° |
3.9 |
4.9 |
5.5 |
5.8 |
| Broad Reach120–135° |
3.6 |
4.6 |
5.1 |
5.3 |
| Run150–180° |
2.9 |
3.6 |
4.1 |
4.3 |
These are simplified estimates based on hull speed (7.0 kts),
SA/D (14.9), 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 Sigma 38 Ss — based on sail area, ballast, and displacement characteristics.
Ghost
Sweet Spot
Reef
Heavy
0–7 kts
7–20 kts
20–28 kts
28+ kts
Ghosting
0–7 kts
Light air, motor-sailing likely. Need patience and a light genoa.
Sweet Spot
7–20 kts
Comfortable under full sail. Best speed-to-comfort ratio.
Time to Reef
20–28 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 Sigma 38 Ss.
|
Sigma 38 Ss |
Bristol 388 |
Farr 38 116 |
Pearson 385 |
Swan 38 Ss |
Yankee 38 |
| Dimensions |
| LOA |
38.3 |
38.3 |
38.3 |
38.3 |
38.3 |
38.2 |
| LWL |
27.5 |
30.6 |
31.2 |
30.0 |
28.7 |
28.8 |
| Beam |
10.3 |
12.1 |
12.0 |
11.6 |
11.6 |
11.8 |
| Displacement |
19 |
19 |
10 |
20 |
18 |
16 |
| Ballast |
6 |
9 |
4 |
9 |
7 |
7 |
| Sail Area |
662 |
744 |
685 |
615 |
686 |
638 |
| Performance |
| PHRF |
— |
— |
— |
180 |
122 |
120 |
| SA/Disp |
14.9 |
16.7 |
22.8 |
13.2 |
15.9 |
16.1 |
| Bal/Disp |
— |
47.0 |
38.7 |
— |
— |
45.8 |
| Comfort |
43.1 |
32.6 |
18.0 |
37.5 |
34.4 |
29.4 |
| Capsize |
1.54 |
1.81 |
2.19 |
1.69 |
1.76 |
1.87 |
| Hull Speed |
7.0 |
7.4 |
7.5 |
7.3 |
7.2 |
7.2 |