申論題

4. Based on the Douglas sea scales, The following are parts of the tables of the state of the sea (The wind generated waves) and the state of swell (The background swell).
State of the sea (wind sea) - Table 1 (partly)


State of the Swell - Table 2 (Partly)



The following wave was what you observed at sea at 18th noon time:
Wave length (L = 210 m) and Wave height (H = 3 m)


Please answer the following questions:

(1) What is the sea degree of this wave? How to express it?