The Rob Roy 23 is aggressively canvassed for its weight, 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 20.8′, the Rob Roy 23 tops out around 6.1 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √20.8′ 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
25.0
Performance-oriented — carries a lot of canvas for its weight.
Ballast / Displacement
29.6%
Light ballast — tends to be tender; reef earlier than the numbers suggest.
Displacement / Length
109
Ultralight — responsive and fast, but carries less stores.
Comfort Ratio
11.1
Quick, snappy motion — better for day sails and racing than long passages.
Capsize Screening
2.13
Above the 2.0 offshore threshold — best suited for coastal and protected waters.
Pounds/Inch Immersion
515lbs
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
11.1
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
2.13
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 Rob Roy 23 sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Cruiser/Racer 90–150
Cruiser 150–210
Heavy Cruiser 210–300
San Juan 28
186s/nm
Ontario 28
195s/nm
Ericson 29
210s/nm
Seafarer 29
210s/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° |
2.9 |
3.6 |
4.1 |
4.2 |
| Close Reach60° |
3.5 |
4.4 |
4.9 |
5.1 |
| Beam Reach90° |
4.3 |
5.4 |
6.0 |
6.5 |
| Broad Reach120–135° |
4.0 |
5.0 |
5.6 |
6.1 |
| Run150–180° |
3.2 |
4.0 |
4.5 |
4.7 |
These are simplified estimates based on hull speed (6.1 kts),
SA/D (25.0), 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 Rob Roy 23 — based on sail area, ballast, and displacement characteristics.
Ghost
Sweet Spot
Reef
Heavy
0–5 kts
5–14 kts
14–22 kts
22+ kts
Ghosting
0–5 kts
Light air, motor-sailing likely. Need patience and a light genoa.
Sweet Spot
5–14 kts
Comfortable under full sail. Best speed-to-comfort ratio.
Time to Reef
14–22 kts
Time to shorten sail. Reef the main, swap to a working jib.
Heavy Weather
22+ 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 Rob Roy 23.
|
Rob Roy 23 |
Aloa 29 |
Ericson 29 |
Ontario 28 |
San Juan 28 |
Seafarer 29 |
| Dimensions |
| LOA |
28.7 |
28.5 |
28.6 |
28.6 |
28.7 |
28.7 |
| LWL |
20.8 |
21.6 |
22.0 |
22.0 |
22.3 |
21.3 |
| Beam |
6.9 |
10.8 |
9.3 |
10.0 |
10.0 |
9.0 |
| Displacement |
2 |
6 |
8 |
6 |
6 |
6 |
| Ballast |
650 |
2 |
3 |
2 |
3 |
2 |
| Sail Area |
264 |
344 |
436 |
400 |
385 |
357 |
| Performance |
| PHRF |
— |
— |
210 |
195 |
186 |
210 |
| SA/Disp |
25.0 |
15.7 |
16.8 |
17.9 |
18.3 |
16.3 |
| Bal/Disp |
29.6 |
33.6 |
45.9 |
42.7 |
50.0 |
— |
| Comfort |
11.1 |
18.1 |
28.3 |
20.4 |
18.4 |
23.3 |
| Capsize |
2.13 |
2.31 |
1.82 |
2.11 |
2.18 |
1.92 |
| Hull Speed |
6.1 |
6.2 |
6.3 |
6.3 |
6.3 |
6.2 |