Swimming pool - lengths not laps

[B0D]

Am I mistaken in saying lengths to describe swimming from one end of the pool to the other? Why do I keep hearing laps when a lap to me is a circuit e.g on a running track. Maybe a lap is two lengths if you were swimming round and round.

You are correct. Though I don't think laps is said for any bad reason. Not an expression that I would correct. It's not like referring to October as being in 'the fall' or calling an outer garment 'pants' instead of trousers.