Sea state refers to the height, period, and character of waves on the surface of a large body of water. The large number of variables involved in creating the sea state cannot be quickly and easily summed, so simpler scales are used to give a rough description of current conditions, primarily for reporting in a ship's log or similar record.
Bowditch 1938
The 1938 edition of the US Navy Hydrographic Office publication No. 9 includes the following scales:
| State of the Sea
|
| Scale | Description | Height of wave
|
| 0 | Calm sea | 0 or less than 1 foot
|
| 1 | Smooth sea | 1 to 2 feet
|
| 2 | Slight sea | 2 to 3 feet
|
| 3 | Moderate sea | 3 to 5 feet
|
| 4 | Rough sea | 5 to 8 feet
|
| 5 | Very rough sea | 8 to 12 feet
|
| 6 | High sea | 12 to 20 feet
|
| 7 | Very high sea | 20 to 40 feet
|
| 8 | Precipitous sea | 40 feet and over
|
| 9 | Confused sea | Record chief direction
|
|
| Character of the sea swell
|
| | 0. None
|
| Low | 1. Short or average
2. Long
|
| Moderate | 3. Short
4. Average
5. Long
|
| Heavy | 6. Short
7. Average
8. Long
|
| | 9. Confused
|
|
- Direction from which swell is coming should be recorded.
- Confused swell should be recorded as "confused northeast," if coming from the direction of northeast.
References
- Bowditch, Nathaniel original; H.O. pub No. 9: American Practical Navigator, Revised Edition 1938; United States Hydrographic Office; Not Copyrighted 1938.