The Aldebaran 815 is modestly canvassed and unhurried, 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 23.8′, the Aldebaran 815 tops out around 6.5 knots in displacement mode — after that, the bow wave outruns the hull and resistance climbs steeply.
1.34 × √23.8′ LWL = 6.5 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
13.9
Modestly canvassed — a comfortable, unhurried cruiser.
Ballast / Displacement
47.6%
Race-oriented ballast ratio — very stiff and powerful.
Displacement / Length
154
Moderate — a good balance of speed and load-carrying ability.
Comfort Ratio
17.1
Quick, snappy motion — better for day sails and racing than long passages.
Capsize Screening
2.01
Above the 2.0 offshore threshold — best suited for coastal and protected waters.
Pounds/Inch Immersion
4lbs
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
17.1
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
2.01
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 Aldebaran 815 sits on the PHRF handicap spectrum — lower numbers mean faster boats.
Cruiser/Racer 90–150
Cruiser 150–210
Heavy Cruiser 210–300
Ericson 27
207s/nm
Islander 27
228s/nm
Coronado 27
231s/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° |
2.4 |
3.0 |
3.3 |
3.5 |
| Close Reach60° |
2.9 |
3.6 |
4.1 |
4.2 |
| Beam Reach90° |
3.5 |
4.4 |
5.0 |
5.4 |
| Broad Reach120–135° |
3.3 |
4.1 |
4.6 |
5.0 |
| Run150–180° |
2.6 |
3.3 |
3.7 |
3.8 |
These are simplified estimates based on hull speed (6.5 kts),
SA/D (13.9), 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 Aldebaran 815 — based on sail area, ballast, and displacement characteristics.
Ghost
Sweet Spot
Reef
Heavy
0–8 kts
8–24 kts
24–34 kts
34+ kts
Ghosting
0–8 kts
Light air, motor-sailing likely. Need patience and a light genoa.
Sweet Spot
8–24 kts
Comfortable under full sail. Best speed-to-comfort ratio.
Time to Reef
24–34 kts
Time to shorten sail. Reef the main, swap to a working jib.
Heavy Weather
34+ 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 Aldebaran 815.
|
Aldebaran 815 |
Cal 2 27 |
Coronado 27 |
Ericson 27 |
Islander 27 |
Nicholson 26 |
| Dimensions |
| LOA |
26.7 |
26.6 |
26.7 |
26.8 |
26.6 |
26.6 |
| LWL |
23.8 |
22.1 |
22.0 |
20.5 |
20.0 |
20.0 |
| Beam |
8.4 |
9.3 |
8.5 |
9.0 |
8.0 |
7.8 |
| Displacement |
4 |
6 |
6 |
6 |
4 |
10 |
| Ballast |
2 |
3 |
2 |
2 |
1 |
— |
| Sail Area |
240 |
374 |
302 |
323 |
325 |
302 |
| Performance |
| PHRF |
— |
— |
231 |
207 |
228 |
— |
| SA/Disp |
13.9 |
16.9 |
14.3 |
14.7 |
20.4 |
10.3 |
| Bal/Disp |
47.6 |
46.3 |
40.8 |
43.9 |
41.5 |
— |
| Comfort |
17.1 |
22.8 |
23.9 |
24.4 |
18.1 |
47.3 |
| Capsize |
2.01 |
1.97 |
1.85 |
1.92 |
2.00 |
1.43 |
| Hull Speed |
6.5 |
6.3 |
6.3 |
6.1 |
6.0 |
6.0 |