Boat container (6)
I believe the answer is:
vessel
I believe this clue is a double definition.
'boat' is the first definition.
(boat is a type of vessel)
'container' is the second definition.
(I know that container can be written as vessel)
(Other definitions for vessel that I've seen before include "one swimming in blood?" , "Ship or large boat" , "Decide on or establish" , "Ship, or receptacle for liquid" , "Kind of ship or a kitchen pot (6)" .)