申論題

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


The following wave was what you observed at sea at noon time :
Wave length (L= 90 m) and Wave height (H= 4.3 m)



Please answer the following questions:

(2) What is the swell degree of this wave? How to express it?