The Irwin 30 is moderately powered for comfortable coastal cruising, with acceptable motion comfort for coastal passages, 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 26.9′, the Irwin 30 tops out around 7.0 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √26.9′ 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.
PHRF Rating
186s/nm
Typical cruiser — designed for comfort and ease, not podium finishes.
SA / Displacement
17.3
Moderate sail power — a capable coastal cruiser, not overpowered.
Ballast / Displacement
44.6%
Stiff enough to carry a big genoa comfortably into moderate breeze.
Displacement / Length
211
Moderate — a good balance of speed and load-carrying ability.
Comfort Ratio
23.3
Acceptable coastal comfort — fine for weekends, notice the chop offshore.
Capsize Screening
1.94
Below the 2.0 offshore threshold — acceptable for ocean passages.
Pounds/Inch Immersion
978lbs
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
23.3
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
1.94
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 30 sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Cruiser/Racer 90–150
Cruiser 150–210
Heavy Cruiser 210–300
Cs 30
150s/nm
Irwin 30 Citation
177s/nm
Columbia 30
180s/nm
Irwin 30
186s/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° |
2.8 |
3.5 |
3.9 |
4.1 |
| Close Reach60° |
3.4 |
4.3 |
4.8 |
5.0 |
| Beam Reach90° |
4.1 |
5.2 |
5.9 |
6.1 |
| Broad Reach120–135° |
3.8 |
4.8 |
5.4 |
5.6 |
| Run150–180° |
3.1 |
3.9 |
4.3 |
4.5 |
These are simplified estimates based on hull speed (7.0 kts),
SA/D (17.3), 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 Irwin 30 — 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 Irwin 30.
|
Irwin 30 |
Columbia 30 |
Cs 30 |
Irwin 30 Citation |
Newport 30 2 |
| Dimensions |
| LOA |
30.0 |
30.0 |
30.0 |
30.0 |
30.0 |
| LWL |
26.9 |
26.5 |
25.4 |
26.9 |
26.5 |
| Beam |
10.2 |
9.5 |
10.3 |
10.0 |
10.7 |
| Displacement |
9 |
10 |
8 |
10 |
8 |
| Ballast |
4 |
— |
3 |
4 |
2 |
| Sail Area |
474 |
515 |
462 |
495 |
414 |
| Performance |
| PHRF |
186 |
180 |
150 |
177 |
— |
| SA/Disp |
17.3 |
16.9 |
18.5 |
16.7 |
16.6 |
| Bal/Disp |
44.6 |
— |
— |
41.4 |
— |
| Comfort |
23.3 |
30.2 |
20.8 |
26.9 |
19.2 |
| Capsize |
1.94 |
1.72 |
2.05 |
1.84 |
2.14 |
| Hull Speed |
7.0 |
6.9 |
6.8 |
7.0 |
6.9 |