Travelling on a gold vessel (7)
I believe the answer is:
gondola
'vessel' is the definition.
(gondola is a kind of vessel)
'travelling on a gold' is the wordplay.
'travelling' indicates an anagram.
'on'+'a'+'gold'='onagold'
'onagold' anagrammed gives 'GONDOLA'.
(Other definitions for gondola that I've seen before include "Boat on Venetian canals" , "Venetian vessel" , "Venice craft" , "Craft for Venetian canals" , "Venetian taxi" .)