Crossword Clue:

a vessel with a single hull

AnswerCrossword Clue
UNIPOLARLike a neuron with a single neurite
ONEMANLike a show with a single performer
SAILBOATSKIPPERCommander of a single-masted vessel
SLOOPBUCKETPail for bailing out a single-masted vessel?