cock·boat 
(kŏkbōt′)
(kŏkbōt′)n.
A small rowboat, especially one used to ferry supplies from ship to shore. Also called cockleboat.
[Middle English cokboot : cok, cockboat (from Anglo-Norman coque, probably ultimately from Latin caudica, from caudex, caudic-, tree trunk) + boot, boat; see BOAT.]