A drama about some ships (6)
I believe the answer is:
armada
'some ships' is the definition.
(group of ships)
'a drama about' is the wordplay.
'about' indicates anagramming the letters.
'drama' with letters rearranged gives 'rmada'.
'a'+'rmada'='ARMADA'
(Other definitions for armada that I've seen before include "A great fleet of warships" , "Large flotilla" , "Old Spanish fleet" , "vessels" , "Fighting unit" .)