Rose to the top of water (8)
I believe the answer is:
surfaced
'rose to the top of water' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for surfaced that I've seen before include "Floated to the top" , "Rose to the top of water" , "Rose to the top or came to attention" , "Came up (for air)" .)