Angler at sea, about last to drop anchor (7)
I believe the answer is:
grapnel
'anchor' is the definition.
(I've seen this before)
'angler at sea about last to drop' is the wordplay.
'at sea' indicates anagramming the letters.
'about' indicates putting letters inside.
'last to' suggests the final letters.
The final letter of 'drop' is 'p'.
'angler' is an anagram of 'granel'.
'granel' going around 'p' is 'GRAPNEL'.
(Other definitions for grapnel that I've seen before include "Rope/hook device" , "Light anchor for small boats" , "Grasping implement" , "Small anchor with several flukes" , "Grappling hook" .)