Calculate SA/D, D/L, comfort ratio, and B/D ratio for any sailboat to understand its performance and seakeeping characteristics.
| Ratio | Range | Classification | Characteristics |
|---|---|---|---|
| SA/D | < 14 | Under-canvassed | Slow in light air; motorsailer tendency |
| 14–18 | Cruiser | Balanced; comfortable offshore | |
| 18–22 | Racer-Cruiser | Lively performance; manageable offshore | |
| > 22 | Racer | Very fast; demanding to sail; not for offshore | |
| D/L | > 300 | Heavy | Sea-kindly; carries supplies; slower |
| 150–300 | Moderate | Best all-around; offshore capable | |
| < 150 | Ultra-light | Fast; performance-oriented; not for bluewater | |
| Comfort | > 40 | Comfortable | Offshore cruiser; handles rough seas well |
| < 20 | Sport | Lively motion; tiring in rough conditions |