It follows a gale at sea too (2,4)
I believe the answer is:
as well
'too' is the definition.
(synonyms)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for as well that I've seen before include "on top" , "with equal effect" , "Also, in addition" , "A swell sort of addition" , "Also, additionally" .)