Use of the word "lap" in swimming

I swear I remember TV announcers of swimming races using the term “lap” to refer to only one length of the pool. I could be mis-remembering.

I acknowledge that most of the time, lap refers to one full trip back to the starting point. But for some reason, I thought it was different for swimming.

A lap is two lengths of the pool. So in the Olympics every event save the 50m Freestyle is at least a lap in length.

This has always been confusing for me. You can swim “laps” or you can swim “lengths”. I believe a length is swimmming from one end to the other while a lap is swimming “up and back” or two lengths. Someone who swims competitively will be by shortly to explain if I got it wrong.

That’s exactly right. Your standard competitive pool is 50 meters in length. One lap is there and back – a total of 100m, or two lengths.

While it may be technically true - a lap is two lengths - in my experience it’s not really used that way (except as below), we use the word “lap” to mean one length.

Usually we don’t refer to the number of lengths anyway, we’d use the actual distance, 400 meters, 500 yards, etc.

If swimmer A has swum fast enough that they are two lengths ahead of swimmer (and are thus side-by-side) we’ll say that swimmer A has “lapped” swimmer B.

But when you run laps at a track, one lap always puts you back where you started. Isn’t that what a lap is supposed to do, put you back where you started?

Absolutely.

I’m not saying it’s the correct usage, just saying that’s how it’s used. If you go to a swim practice and ask how many laps 500 yards is, they’ll say 20.

How it’s used by whom? Certainly not any competitive swimmer I’ve met, and I’ve met a lot because I used to be one (alas, that was many moons ago indeed.)

This is a long established usage in swimming.

Here’s OED:

Ok, well in all my years of competitive swimming, I don’t remember ever hearing it used that way. Again though, we didn’t really talk about “laps” as in “I’m going to go swim 40 laps”. We’d say, “I’m going to go do a 1000”.

So maybe most people do refer to 2 lengths as a lap, I’ve just never really heard that.

Conway’s interpretation was why I asked the question. Swimming seems to be the one exception to the standard definition of lap. And at least one dictionary agrees:

2.
a. One complete round or circuit, especially of a racetrack.
b. One complete length of a straight course, as of a swimming pool.

I did competitive swimming all through high school. We never really used the term “lap,” because of the possibility of confusion. We used the term “lengths.”

I know that when we swam the 500-yard freestyle, there were cards that were used to keep track of how many lengths the swimmers had gone. The cards could be lowered into the water for the swimmer’s benefit, and were numbered from 1 to 20, corresponding to twenty 25-yard lengths for a 500-yard swim. (In practice, you lowered the odd numbers into the water as the swimmer approached, indicating 1, 3, 5, …, 17, and 19 lengths completed.

That being said, I have always understood a “lap” to mean two lengths. After all, when you “lapped” someone, you were two lengths ahead of them.

It appears that the verb and noun forms of the word are not entirely analogous…in swimming anyway.

That’s a good point – when I was swimming we always talked about the actual distance and didn’t really use “lap” or “length” very often at all. So maybe the confusion in terminology is simply because nobody uses those words!

Not sure how you came to this conclusion. Maybe swimmers themselves don’t use it, but it’s certainly used quite frequently in the context of swimming based on everything I’ve read or watched. The dictionary definition to which I linked gives swimming as its only example.