The Grampian 46 is moderately powered for comfortable coastal cruising, with a steady, comfortable ride offshore.
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 33.0′, the Grampian 46 tops out around 7.7 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √33.0′ LWL = 7.7 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
16.6
Moderate sail power — a capable coastal cruiser, not overpowered.
Ballast / Displacement
36.0%
Typical cruising ballast — balanced stability and motion underway.
Displacement / Length
311
Moderate-heavy — carries provisions well, deliberate in light air.
Comfort Ratio
38.3
Good offshore comfort — steady enough for multi-day passages.
Capsize Screening
1.64
Below the 2.0 offshore threshold — acceptable for ocean passages.
SA/Disp (Calculated)
14.0
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
38.3
Good offshore comfort — steady enough for multi-day passages.
Under 20 — Snappy, racing motion
20–30 — Acceptable coastal
30–40 — Good offshore comfort
Over 40 — Very comfortable offshore
Capsize Screening Formula
1.64
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 Grampian 46 sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Racer 0–90
Cruiser/Racer 90–150
Ericson 46
72s/nm
Tartan 4600
75s/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 |
4.5 |
| 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 |
5.9 |
6.1 |
| Run150–180° |
3.3 |
4.2 |
4.7 |
4.9 |
These are simplified estimates based on hull speed (7.7 kts),
SA/D (16.6), 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 Grampian 46 — based on sail area, ballast, and displacement characteristics.
Ghost
Sweet Spot
Reef
Heavy
0–7 kts
7–20 kts
20–28 kts
28+ kts
Ghosting
0–7 kts
Light air, motor-sailing likely. Need patience and a light genoa.
Sweet Spot
7–20 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 Grampian 46.
|
Grampian 46 |
Ericson 46 |
Kelly Peterson 46 |
Morgan 46 Scheel |
Seafarer 46 |
Tartan 4600 |
| Dimensions |
| LOA |
46.0 |
45.8 |
46.3 |
46.0 |
46.0 |
46.2 |
| LWL |
33.0 |
35.0 |
40.8 |
39.3 |
31.0 |
39.6 |
| Beam |
12.0 |
13.3 |
13.3 |
13.5 |
11.0 |
14.3 |
| Displacement |
25 |
31 |
33 |
30 |
27 |
28 |
| Ballast |
9 |
16 |
11 |
3 |
11 |
8 |
| Sail Area |
881 |
1 |
1 |
876 |
938 |
— |
| Performance |
| PHRF |
— |
72 |
— |
— |
— |
75 |
| SA/Disp |
16.6 |
17.1 |
17.1 |
14.6 |
16.7 |
— |
| Bal/Disp |
36.0 |
52.4 |
— |
— |
— |
30.4 |
| Comfort |
38.3 |
40.8 |
38.5 |
35.1 |
48.2 |
— |
| Capsize |
1.64 |
1.68 |
1.66 |
1.74 |
1.47 |
— |
| Hull Speed |
7.7 |
7.9 |
8.6 |
8.4 |
7.5 |
— |