The Lm 27 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 23.3′, the Lm 27 tops out around 6.5 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √23.3′ LWL = 6.5 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
12.2
Modestly canvassed — a comfortable, unhurried cruiser.
Ballast / Displacement
45.0%
Race-oriented ballast ratio — very stiff and powerful.
Displacement / Length
312
Moderate-heavy — carries provisions well, deliberate in light air.
Comfort Ratio
29.7
Acceptable coastal comfort — fine for weekends, notice the chop offshore.
Capsize Screening
1.75
Below the 2.0 offshore threshold — acceptable for ocean passages.
Pounds/Inch Immersion
751lbs
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
29.7
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
1.75
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 Lm 27 sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Cruiser/Racer 90–150
Cruiser 150–210
Heavy Cruiser 210–300
Morgan 27
174s/nm
Cal 27
198s/nm
Cape Dory 270
219s/nm
Contest 27
228s/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 |
3.1 |
3.3 |
| Close Reach60° |
2.7 |
3.4 |
3.8 |
4.0 |
| Beam Reach90° |
3.3 |
4.2 |
4.7 |
4.8 |
| Broad Reach120–135° |
3.0 |
3.8 |
4.3 |
4.5 |
| Run150–180° |
2.4 |
3.1 |
3.4 |
3.6 |
These are simplified estimates based on hull speed (6.5 kts),
SA/D (12.2), 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 Lm 27 — 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 Lm 27.
|
Lm 27 |
Cal 27 |
Cape Dory 270 |
Contessa 27 |
Contest 27 |
Morgan 27 |
| Dimensions |
| LOA |
27.4 |
27.3 |
27.3 |
27.5 |
27.3 |
27.5 |
| LWL |
23.3 |
22.3 |
20.8 |
23.5 |
21.7 |
25.0 |
| Beam |
9.0 |
9.0 |
9.4 |
10.0 |
8.9 |
9.8 |
| Displacement |
8 |
5 |
8 |
5 |
5 |
7 |
| Ballast |
3 |
2 |
3 |
2 |
2 |
3 |
| Sail Area |
323 |
350 |
398 |
413 |
346 |
373 |
| Performance |
| PHRF |
— |
198 |
219 |
— |
228 |
174 |
| SA/Disp |
12.2 |
18.3 |
15.5 |
20.7 |
18.6 |
16.4 |
| Bal/Disp |
45.0 |
50.5 |
38.8 |
45.4 |
46.8 |
— |
| Comfort |
29.7 |
18.8 |
28.8 |
16.8 |
18.6 |
20.0 |
| Capsize |
1.75 |
2.06 |
1.86 |
2.24 |
2.06 |
2.06 |
| Hull Speed |
6.5 |
6.3 |
6.1 |
6.5 |
6.2 |
6.7 |