The Gulfstar 47 Sailmaster is modestly canvassed and unhurried, with a gentle bluewater motion.
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 40.5′, the Gulfstar 47 Sailmaster tops out around 8.5 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √40.5′ LWL = 8.5 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
13.1
Modestly canvassed — a comfortable, unhurried cruiser.
Ballast / Displacement
27.6%
Light ballast — tends to be tender; reef earlier than the numbers suggest.
Displacement / Length
255
Moderate-heavy — carries provisions well, deliberate in light air.
Comfort Ratio
41.7
Very comfortable in a seaway — a genuine bluewater motion.
Capsize Screening
1.65
Below the 2.0 offshore threshold — acceptable for ocean passages.
SA/Disp (Calculated)
11.4
Computed from measured I/J/P/E rather than reported sail area.
Pounds/Inch Immersion
12lbs
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
41.7
Very comfortable in a seaway — a genuine bluewater motion.
Under 20 — Snappy, racing motion
20–30 — Acceptable coastal
30–40 — Good offshore comfort
Over 40 — Very comfortable offshore
Capsize Screening Formula
1.65
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 Gulfstar 47 Sailmaster sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Racer 0–90
Cruiser/Racer 90–150
Cruiser 150–210
Peterson 46
87s/nm
Catalina 470
102s/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° |
3.0 |
3.8 |
4.3 |
4.4 |
| Close Reach60° |
3.7 |
4.6 |
5.2 |
5.4 |
| Beam Reach90° |
4.5 |
5.7 |
6.3 |
6.6 |
| Broad Reach120–135° |
4.1 |
5.2 |
5.8 |
6.1 |
| Run150–180° |
3.3 |
4.2 |
4.7 |
4.9 |
These are simplified estimates based on hull speed (8.5 kts),
SA/D (13.1), 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 Gulfstar 47 Sailmaster — based on sail area, ballast, and displacement characteristics.
Ghost
Sweet Spot
Reef
Heavy
0–8 kts
8–20 kts
20–28 kts
28+ kts
Ghosting
0–8 kts
Light air, motor-sailing likely. Need patience and a light genoa.
Sweet Spot
8–20 kts
Comfortable under full sail. Best speed-to-comfort ratio.
Time to Reef
20–28 kts
Time to shorten sail. Reef the main, swap to a working jib.
Heavy Weather
28+ 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 Gulfstar 47 Sailmaster.
|
Gulfstar 47 Sailmaster |
Catalina 470 |
Mariner 47 Brewer |
Ocean Cruising 48 |
Peterson 46 |
Tayana 47 Cc |
| Dimensions |
| LOA |
47.4 |
47.0 |
47.5 |
47.6 |
47.5 |
47.0 |
| LWL |
40.5 |
41.0 |
37.0 |
36.0 |
40.6 |
40.3 |
| Beam |
13.8 |
14.2 |
13.8 |
13.8 |
13.0 |
14.5 |
| Displacement |
38 |
27 |
29 |
29 |
33 |
35 |
| Ballast |
10 |
10 |
11 |
11 |
— |
11 |
| Sail Area |
923 |
1,010 |
— |
— |
878 |
1 |
| Performance |
| PHRF |
— |
102 |
— |
— |
87 |
— |
| SA/Disp |
13.1 |
17.9 |
— |
— |
13.6 |
20.7 |
| Bal/Disp |
27.6 |
40.0 |
39.0 |
39.1 |
— |
33.4 |
| Comfort |
41.7 |
28.7 |
— |
— |
39.6 |
36.4 |
| Capsize |
1.65 |
1.86 |
— |
— |
1.62 |
1.78 |
| Hull Speed |
8.5 |
8.7 |
— |
— |
8.5 |
8.5 |