Lengths or laps?

[6demandingchildren]

When in the swimming pool you swim lengths, DH says it's laps and his sports watch also says laps.
You run laps not swim them.
Who is right?

If it's all around the pool, it's a lap.

If it's up and down a lane, it's a length.

That said, I can't be sure what people who wear "sports watches" are doing, as they seem to spend more time fiddling with their tech than actually swimming.

We just swim up and down the lanes.
And his sports watch is normally quite clever