The Neptune 24 Cb is well-powered with enough sail area to move in light air, with a quick, snappy motion best suited to day sailing.
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 21.0′, the Neptune 24 Cb tops out around 6.1 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √21.0′ LWL = 6.1 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
18.5
Powerful cruiser/racer — quick in light air, reef early when it pipes up.
Ballast / Displacement
37.5%
Typical cruising ballast — balanced stability and motion underway.
Displacement / Length
154
Moderate — a good balance of speed and load-carrying ability.
Comfort Ratio
14.2
Quick, snappy motion — better for day sails and racing than long passages.
Capsize Screening
2.17
Above the 2.0 offshore threshold — best suited for coastal and protected waters.
SA/Disp (Calculated)
16.8
Computed from measured I/J/P/E rather than reported sail area.
Pounds/Inch Immersion
599lbs
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
14.2
Quick, snappy motion — better for day sails and racing than long passages.
Under 20 — Snappy, racing motion
20–30 — Acceptable coastal
30–40 — Good offshore comfort
Over 40 — Very comfortable offshore
Capsize Screening Formula
2.17
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 Neptune 24 Cb sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Cruiser/Racer 90–150
Cruiser 150–210
Heavy Cruiser 210–300
Wavelength 24
162s/nm
Neptune 24 Fk
222s/nm
San Juan 24
222s/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° |
2.5 |
3.2 |
3.6 |
3.8 |
| Close Reach60° |
3.1 |
3.9 |
4.4 |
4.5 |
| Beam Reach90° |
3.8 |
4.8 |
5.3 |
5.8 |
| Broad Reach120–135° |
3.5 |
4.4 |
4.9 |
5.3 |
| Run150–180° |
2.8 |
3.5 |
3.9 |
4.1 |
These are simplified estimates based on hull speed (6.1 kts),
SA/D (18.5), 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 Neptune 24 Cb — based on sail area, ballast, and displacement characteristics.
Ghost
Sweet Spot
Reef
Heavy
0–6 kts
6–18 kts
18–26 kts
26+ kts
Ghosting
0–6 kts
Light air, motor-sailing likely. Need patience and a light genoa.
Sweet Spot
6–18 kts
Comfortable under full sail. Best speed-to-comfort ratio.
Time to Reef
18–26 kts
Time to shorten sail. Reef the main, swap to a working jib.
Heavy Weather
26+ 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 Neptune 24 Cb.
|
Neptune 24 Cb |
Cc 24 |
J24 |
Neptune 24 Fk |
San Juan 24 |
Wavelength 24 |
| Dimensions |
| LOA |
24.0 |
24.0 |
24.0 |
24.0 |
24.0 |
24.0 |
| LWL |
21.0 |
19.5 |
20.0 |
21.0 |
19.5 |
20.3 |
| Beam |
8.0 |
8.8 |
8.9 |
8.0 |
8.0 |
9.0 |
| Displacement |
3 |
3 |
3 |
3 |
3 |
2 |
| Ballast |
1 |
1 |
950 |
1 |
1 |
1 |
| Sail Area |
250 |
252 |
262 |
250 |
246 |
288 |
| Performance |
| PHRF |
— |
— |
— |
222 |
222 |
162 |
| SA/Disp |
18.5 |
18.6 |
19.8 |
18.5 |
18.2 |
25.1 |
| Bal/Disp |
37.5 |
32.8 |
— |
— |
51.6 |
— |
| Comfort |
14.2 |
13.1 |
12.3 |
14.2 |
14.9 |
9.7 |
| Capsize |
2.17 |
2.39 |
2.44 |
2.17 |
2.17 |
2.66 |
| Hull Speed |
6.1 |
5.9 |
6.0 |
6.1 |
5.9 |
6.0 |