See a floating structure as a boat (5)
I believe the answer is:
craft
'a boat' is the definition.
(thesaurus)
'see a floating structure' is the wordplay.
'see' becomes 'c' (the word for the letter, according to Chambers).
'a floating structure' becomes 'raft' (I've seen this before).
'c'+'raft'='CRAFT'
'as' is the link.
(Other definitions for craft that I've seen before include "Vessel for a skilled occupation" , "Skill in making things by hand" , "Workmanship" , "Cunning - trade" , "Skill; ship" .)