The Irwin 41 is moderately powered for comfortable coastal cruising, with a steady, comfortable ride offshore, designed for cruising comfort rather than racing.
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 35.1′, the Irwin 41 tops out around 7.9 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √35.1′ LWL = 7.9 kts
Performance Ratios
Racing handicap, sail-carrying power, stability and comfort — and what each one actually tells you about a day on the water.
PHRF Rating
153s/nm
Typical cruiser — designed for comfort and ease, not podium finishes.
SA / Displacement
15.1
Moderate sail power — a capable coastal cruiser, not overpowered.
Comfort Ratio
32.6
Good offshore comfort — steady enough for multi-day passages.
Capsize Screening
1.85
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
32.6
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
1.85
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 Irwin 41 sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Racer 0–90
Cruiser/Racer 90–150
Cruiser 150–210
Passport 41
132s/nm
Cooper 416
135s/nm
Irwin 41
153s/nm
Typical cruiser — designed for comfort and ease, not podium finishes.
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° |
3.0 |
3.8 |
4.2 |
4.4 |
| Close Reach60° |
3.6 |
4.6 |
5.1 |
5.3 |
| Beam Reach90° |
4.4 |
5.6 |
6.3 |
6.5 |
| Broad Reach120–135° |
4.1 |
5.2 |
5.8 |
6.0 |
| Run150–180° |
3.3 |
4.1 |
4.6 |
4.8 |
These are simplified estimates based on hull speed (7.9 kts),
SA/D (15.1), 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 Irwin 41 — 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 Irwin 41.
|
Irwin 41 |
Cooper 416 |
Morgan Out Island 416 |
Passport 41 |
Tartan 41 Passagemaker |
Us 42 |
| Dimensions |
| LOA |
41.5 |
41.5 |
41.3 |
41.3 |
41.3 |
41.5 |
| LWL |
35.1 |
32.5 |
34.0 |
33.4 |
32.3 |
32.5 |
| Beam |
13.5 |
14.0 |
13.8 |
12.7 |
13.3 |
14.0 |
| Displacement |
25 |
24 |
27 |
22 |
24 |
24 |
| Ballast |
8 |
10 |
9 |
8 |
— |
10 |
| Sail Area |
803 |
723 |
877 |
— |
788 |
— |
| Performance |
| PHRF |
153 |
135 |
— |
132 |
— |
— |
| SA/Disp |
15.1 |
14.0 |
15.7 |
— |
15.1 |
— |
| Bal/Disp |
— |
43.8 |
33.3 |
37.3 |
— |
43.8 |
| Comfort |
32.6 |
31.4 |
34.9 |
— |
34.1 |
— |
| Capsize |
1.85 |
1.95 |
1.85 |
— |
1.84 |
— |
| Hull Speed |
7.9 |
7.6 |
7.8 |
— |
7.6 |
— |