Reversible vessel (5)
I believe the answer is:
kayak
I believe this is a double definition.
'reversible' is the first definition.
'vessel' is the second definition.
(kayak is a kind of vessel)
(Other definitions for kayak that I've seen before include "Small canoe with a light frame" , "Lightweight canoe" , "Palindromic canoe used by eskimos" , "Small canoe - a palindrome" , "Arctic canoe" .)