cockboat
Concise Oxford English Dictionary © 2008 Oxford University Press:
cockboat/ˈkɒkbəʊt/
▶noun a small boat towed behind a larger vessel.
– origin ME: from obs. cock ‘small boat’ (from OFr. coque, based on L. caudex, codex ‘block of wood’) + boat.
'cockboat' also found in these Oxford entries:

