Apple Watch Pool Swim Lengths or laps

Your confusion is understandable. Most people - and the Apple Watch 3 I have - get this wrong.

A lap means (in all applicable sports) returning to your starting point; which in swimming equates to down-and back. (In track & field or car racing, going once around the circuit.)

So in swimming a LENGTH in a 25-yard pool is swimming that one-way distance (25 yards). While a LAP is down-and-back (50 yards). By contrast, a LENGTH in an Olympic Pool is 50 meters and a lap is 100 meters.

So back to the 25 yard pool. A mile would be 1,760 yards ..... or about 70 lengths .... or 35 laps.

So when I swim a mile in a 25-yard pool my Apple Watch erroneously records it as 70 laps when it should be 35 laps.

Hope this helps.

There is really no concept of or support for lap in the Pool Swim workout presently. Its only about the pool length, and then you can see the splits by 100/50/25 units also.

So it looks like half of your laps did not get recorded at all. How are the timings looking, is that consistent?