"possibly the Du. boomken may formerly have been used in this special sense. The spelling bumpkin is now more usual.] ‘A short boom projecting from each bow of a ship, to extend the lower edge of the foresail to windward.’"

May this DU. person add the comment that the word 'boomken'is Dutch for 'small tree' up till this day and 'boom' = 'tree'.
So the wood connection also to vessel is clear.