The First 45F5 Beneteau is aggressively canvassed for its weight, 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 39.0′, the First 45F5 Beneteau tops out around 8.4 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √39.0′ LWL = 8.4 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
23.6
Performance-oriented — carries a lot of canvas for its weight.
Ballast / Displacement
36.2%
Typical cruising ballast — balanced stability and motion underway.
Displacement / Length
174
Moderate — a good balance of speed and load-carrying ability.
Comfort Ratio
25.9
Acceptable coastal comfort — fine for weekends, notice the chop offshore.
Capsize Screening
1.96
Below the 2.0 offshore threshold — acceptable for ocean passages.
SA/Disp (Calculated)
18.2
Computed from measured I/J/P/E rather than reported sail area.
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
25.9
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
1.96
Below the 2.0 offshore threshold — acceptable for ocean passages.
Under 2.0 — Acceptable for offshore
Over 2.0 — Coastal / protected waters
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° |
3.9 |
5.0 |
5.6 |
5.8 |
| Close Reach60° |
4.8 |
6.0 |
6.7 |
7.0 |
| Beam Reach90° |
5.8 |
7.4 |
8.3 |
9.0 |
| Broad Reach120–135° |
5.4 |
6.8 |
7.6 |
8.3 |
| Run150–180° |
4.3 |
5.5 |
6.1 |
6.4 |
These are simplified estimates based on hull speed (8.4 kts),
SA/D (23.6), 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 First 45F5 Beneteau — based on sail area, ballast, and displacement characteristics.
Ghost
Sweet Spot
Reef
Heavy
0–5 kts
5–16 kts
16–24 kts
24+ kts
Ghosting
0–5 kts
Light air, motor-sailing likely. Need patience and a light genoa.
Sweet Spot
5–16 kts
Comfortable under full sail. Best speed-to-comfort ratio.
Time to Reef
16–24 kts
Time to shorten sail. Reef the main, swap to a working jib.
Heavy Weather
24+ 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 First 45F5 Beneteau.
|
First 45F5 Beneteau |
Beneteau 461 |
First 45 Beneteau Farr |
First 477 Beneteau |
Sun Odyssey 47 Jeanneau |
X46 |
| Dimensions |
| LOA |
46.6 |
46.6 |
46.6 |
47.0 |
47.0 |
46.2 |
| LWL |
39.0 |
39.4 |
39.0 |
41.3 |
40.7 |
40.5 |
| Beam |
13.9 |
14.0 |
13.9 |
14.8 |
14.4 |
14.0 |
| Displacement |
23 |
20 |
23 |
25 |
28 |
24 |
| Ballast |
8 |
7 |
8 |
8 |
10 |
9 |
| Sail Area |
1 |
832 |
1,194 |
1,033 |
1,152 |
1 |
| Performance |
| SA/Disp |
23.6 |
17.6 |
23.6 |
19.2 |
19.6 |
21.9 |
| Bal/Disp |
36.2 |
35.8 |
36.2 |
33.3 |
35.4 |
— |
| Comfort |
25.9 |
23.3 |
25.9 |
25.3 |
— |
26.2 |
| Capsize |
1.96 |
2.03 |
1.96 |
2.01 |
— |
1.95 |
| Hull Speed |
8.4 |
8.4 |
8.4 |
8.6 |
— |
8.5 |