Fleet of warships a right crazy first appearance (6)
I believe the answer is:
armada
'fleet of warships' is the definition.
(I've seen this in another clue)
'a right crazy first appearance' is the wordplay.
'a right' becomes 'ar' (I've seen this in other clues).
'crazy' becomes 'mad' (synonyms).
'first appearance' becomes 'a' (ast letter of 'appearance').
'ar'+'mad'+'a'='ARMADA'
(Other definitions for armada that I've seen before include "Old Spanish fleet" , "group of ships" , "sea-borne unit" , "1588 sea battle" , "Navy" .)