The Aura 51 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.
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
22.8
Performance-oriented — carries a lot of canvas for its weight.
Displacement / Length
219
Moderate — a good balance of speed and load-carrying ability.
Comfort Ratio
17.0
Quick, snappy motion — better for day sails and racing than long passages.
Capsize Screening
3.11
Above the 2.0 offshore threshold — best suited for coastal and protected waters.
Pounds/Inch Immersion
25lbs
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
17.0
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
3.11
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
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° |
4.1 |
5.2 |
5.8 |
6.0 |
| Close Reach60° |
5.0 |
6.3 |
7.0 |
7.3 |
| Beam Reach90° |
6.1 |
7.7 |
8.6 |
8.8 |
| Broad Reach120–135° |
5.6 |
7.1 |
7.9 |
8.3 |
| Run150–180° |
4.5 |
5.7 |
6.3 |
6.6 |
These are simplified estimates based on hull speed (8.8 kts),
SA/D (22.8), 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 Aura 51 — 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 Aura 51.
|
Aura 51 |
Cr 490 Ds |
Italia 1498 |
Moody 48 Ds |
Xc 50 |
Xp 50 |
| Dimensions |
| LOA |
51.0 |
50.9 |
50.8 |
50.6 |
51.2 |
51.1 |
| LWL |
— |
45.3 |
43.0 |
45.4 |
44.3 |
43.7 |
| Beam |
26.5 |
15.5 |
14.2 |
15.9 |
15.1 |
14.5 |
| Displacement |
39 |
38 |
22 |
46 |
35 |
29 |
| Ballast |
— |
— |
— |
— |
15 |
12 |
| Sail Area |
1 |
1,259 |
1 |
1 |
1 |
1 |
| Performance |
| SA/Disp |
22.8 |
17.7 |
29.3 |
17.5 |
20.3 |
27.4 |
| Bal/Disp |
— |
— |
— |
— |
44.9 |
41.2 |
| Comfort |
17.0 |
33.3 |
21.9 |
38.6 |
31.8 |
28.6 |
| Capsize |
3.11 |
1.83 |
2.03 |
1.77 |
1.84 |
1.87 |
| Hull Speed |
8.8 |
9.0 |
8.8 |
9.0 |
8.9 |
8.9 |