The Beneteau 347 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 28.6′, the Beneteau 347 tops out around 7.2 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √28.6′ LWL = 7.2 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
26.7
Performance-oriented — carries a lot of canvas for its weight.
Ballast / Displacement
38.1%
Stiff enough to carry a big genoa comfortably into moderate breeze.
Displacement / Length
184
Moderate — a good balance of speed and load-carrying ability.
Comfort Ratio
20.3
Acceptable coastal comfort — fine for weekends, notice the chop offshore.
Capsize Screening
2.08
Above the 2.0 offshore threshold — best suited for coastal and protected waters.
SA/Disp (Calculated)
218.1
Computed from measured I/J/P/E rather than reported sail area.
Pounds/Inch Immersion
7lbs
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
20.3
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
2.08
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 Beneteau 347 sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Racer 0–90
Cruiser/Racer 90–150
Cruiser 150–210
Pearson 34
144s/nm
Tartan 33
153s/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° |
3.4 |
4.3 |
4.8 |
5.0 |
| Close Reach60° |
4.1 |
5.2 |
5.8 |
6.0 |
| Beam Reach90° |
5.0 |
6.3 |
7.1 |
7.7 |
| Broad Reach120–135° |
4.6 |
5.9 |
6.5 |
7.1 |
| Run150–180° |
3.7 |
4.7 |
5.2 |
5.5 |
These are simplified estimates based on hull speed (7.2 kts),
SA/D (26.7), 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 Beneteau 347 — 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 Beneteau 347.
|
Beneteau 347 |
Hallberg Rassy 34 |
Hp 1030 |
Pearson 34 |
S2 103 |
Tartan 33 |
| Dimensions |
| LOA |
33.7 |
33.7 |
33.8 |
33.8 |
33.8 |
33.7 |
| LWL |
28.6 |
28.5 |
31.2 |
28.1 |
28.0 |
28.8 |
| Beam |
11.1 |
11.2 |
10.8 |
11.2 |
11.3 |
11.0 |
| Displacement |
9 |
11 |
7 |
11 |
10 |
10 |
| Ballast |
3 |
4 |
2 |
4 |
4 |
4 |
| Sail Area |
756 |
592 |
775 |
550 |
564 |
531 |
| Performance |
| PHRF |
— |
— |
— |
144 |
— |
153 |
| SA/Disp |
26.7 |
18.5 |
33.1 |
17.6 |
18.9 |
18.4 |
| Bal/Disp |
38.1 |
39.6 |
36.4 |
— |
— |
— |
| Comfort |
20.3 |
24.0 |
14.9 |
23.4 |
21.5 |
21.0 |
| Capsize |
2.08 |
1.98 |
2.22 |
2.00 |
2.07 |
2.04 |
| Hull Speed |
7.2 |
7.2 |
7.5 |
7.1 |
7.1 |
7.2 |