Methodology
How SailPages classifies, rates, and compares sailboats.
How It Works — A Real Example
CATALINA 30
Offshore CruiserThe Catalina 30 is classified as an Offshore Cruiser. Its performance values are compared against the average of all 2342 boats in that class:
Each boat's value is compared to the average of all boats in its class:(boat value - class avg) / class avg × 100
For Capsize Screening, the sign is inverted — a lower raw number means more stability, so +5% means 5% more stable (lower capsize ratio) than the class average.
Peer Classification System
Every sailboat is assigned to a peer class based on its size, stability, and performance characteristics. Metrics are then compared against the average within that class — not against all 9,250 boats. This means a coastal cruiser is judged against other coastal cruisers, not against ocean-crossing bluewater boats or racing dinghies.
Heavy, stable boats designed for open ocean passages and circumnavigation. High comfort ratios and excellent capsize resistance.
Criteria: LOA 35-55ft, Comfort Ratio ≥ 30, Capsize Screening < 2.0
Capable cruising boats suitable for coastal passages and moderate ocean crossings. Good balance of comfort and performance.
Criteria: LOA 28-50ft, Comfort Ratio 20-30, Capsize Screening < 2.2
Designed for coastal waters and protected anchorages. Comfortable for weekends and coastal hops.
Criteria: LOA 25-40ft, Comfort Ratio 15-20
Boats that balance racing performance with cruising comfort. Higher sail area ratios than pure cruisers.
Criteria: LOA 25-50ft, SA/Displacement > 18
Built for speed. High sail area ratios, light displacement, optimized for racing.
Criteria: SA/Displacement > 22
Small keelboats and trailerable sailboats for day sailing and weekend use. Typically 16-25ft with basic accommodation.
Criteria: LOA 16-25ft
Small open boats under 16ft for racing, learning, and recreational sailing. No cabin or overnight capability.
Criteria: LOA under 16ft
Multi-hull designs offering stability, speed, and spacious accommodations. Different performance characteristics than monohulls.
Criteria: Multi-hull design (catamaran, trimaran)
Performance Metrics Explained
Comfort Ratio
Formula: Displacement / (0.65 × (0.7 × LWL + 0.3 × LOA) × Beam^1.33)
Developed by Ted Brewer, this measures how comfortable the motion will be in a seaway. Higher values indicate a heavier, more stable boat that will absorb wave energy rather than transmitting it to the crew. A ratio above 30 indicates a comfortable offshore cruiser. Below 20 suggests a sportier, more active ride.
Capsize Screening Formula
Formula: Beam / (Displacement / 64.2)^(1/3)
Developed after the 1979 Fastnet Race disaster that killed 15 sailors, this formula screens for vulnerability to capsize. The critical threshold is 2.0 — boats below 2.0 are considered to have adequate stability for offshore sailing. The lower the number, the more resistant to capsize. This is the single most important safety metric for offshore sailors.
Sail Area / Displacement Ratio
Formula: Sail Area / (Displacement / 64.2)^(2/3)
Measures how much sail power a boat has relative to its weight. Higher values mean more power and better light-air performance. Racing boats typically exceed 20, while heavy cruisers are often below 15.
Displacement / Length Ratio
Formula: (Displacement / 2240) / (0.01 × LWL)^3
Indicates how heavy a boat is for its length. Values above 300 are heavy-displacement cruisers with steady, predictable motion. Below 200 are lighter boats that are faster but more affected by waves.
Current Class Averages
These are the averages each boat is compared against within its peer class.
| Class | Boats | Avg Comfort | Avg Capsize | Avg SA/Disp |
|---|---|---|---|---|
| Bluewater Cruiser | 1363 | 37.7 | 1.71 | 15.2 |
| Offshore Cruiser | 2390 | 24.8 | 1.94 | 17.5 |
| Coastal Cruiser | 904 | 17.8 | 2.13 | 19.5 |
Data Sources
Color Coding System
Performance bars use a color system relative to what's good for cruising: