Conveyance of burden in charge of sailor (7)
I believe the answer is:
taxicab
'conveyance' is the definition.
(taxicab is a kind of conveyance)
'burden in charge of sailor' is the wordplay.
'burden' becomes 'tax' (I've seen this before).
'in charge of' becomes 'ic'.
'sailor' becomes 'ab' (abbreviation for able seaman).
'tax'+'ic'+'ab'='TAXICAB'
'of' is the link.
(Other definitions for taxicab that I've seen before include "Vehicle for hire" , "transport" , "Hire car" , "Licensed passenger vehicle" .)