Swimmer's bottom to top flow (7)
I believe the answer is:
emanate
'flow' is the definition.
(I've seen this in another clue)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for emanate that I've seen before include "Flow or proceed from" , "Come out (of source)" , "Issue or spread out from a source" , "spring" , "Emerge or originate" .)