
| State of the sea | Waves average height | |||
| 0 | Calm (glassy) | - | ||
| 1 | Calm (rippled) | 0 - 0,10 metres | ||
| 2 | Smooth | 0,10 - 0,50 metres | ||
| 3 | Slight | 0,50 - 1,25 metres | ||
| 4 | Moderate | 1,25 - 2,50 metres | ||
| 5 | Rough | 2,50 - 4 metres | ||
| 6 | Very rough | 4 - 6 metres | ||
| 7 | High | 6 - 9 metres | ||
| 8 | Very high | 9 - 14 metres | ||
| 9 | Phenomenal | over 14 metres |