boat length (racing unit); distance between boats
Used in boat racing to measure the distance between boats, where one 艇身 equals the length of one boat. Functions as both a noun and a counter.
His boat won by a margin of two boat lengths.
In a race, a lead of one boat length can sometimes decide the outcome.
half a boat length
Compound of 艇 (boat) and 身 (body), literally 'boat body', used as a unit of length in boat racing.