I mostly agree with this. But I also think you should recognize that there is a consensus among experts here. Take that for what it is worth.

But in your call for hard data, here you go. A month ago I swam with a watch. I wear a watch occasionally. On longer sets I can live with the imprecision. And as much as we joke the reason I am most likely to wear it is for Strava.

The data can be found below. The pool was SCM, not LCM. Here is the list of problems: THe

1) I did 2 600s warm up. Each 600 was 100 freestyle / 25 kick / 25 back x 4. The first 600 the data capture was good. The second 600 the data missed 50M. I get the watch misses kicking. I wish it was consistent. Miss all of it or none of it.

Next I did 8 x 100's on 1:26 (dont ask) with a goal to hold 1:14 on all of them. It went really well. So well that with 2 left I decided to add a 100 and drop down to 1:13. My times - without question - were 1:14 on the first 6, 1:13 on the last 3.

Yet my watch shows me says I went a 1:15 on two of them (I didn't) and has me at 1:14.9 on # 8 which was most certainly a 1:13

Because the watch records 25M splits, I can look a little deeper. Let's compare two of the 100's:

Number 6 / Number 7
19.9 / 19.2
18.6 / 18.8
19.1 / 18.4
17.9 / 17.3
1:15.4 / 1:13.6

According to the watch I was faster on the 2nd 25 on the slower one. That is wrong. In fact I went back and that is the fastest 2nd 25 for all the repeats. So not only is the data wrong, it isn't even user error (which is what I would have assumed). Another thing that is wrong is the first 25 split. This isn't a surprise because of the a fore mentioned problems of coordinating the start with a streamline. ALl the first 25 splits are wrong. I think that 19.9 was wrong by a lot. I doubt I did a single lead off 25 slower than 19.0. There is not consistency in the errors so the data is just...useless.

Now I think you want to make the argument that the data is good enough. A few 1-2% errors here or there don't mean that much. I coached for one season collegiality. I have swam competitively for the last 36 years. The difference between what I actually did and what the watch recorded is the difference between knowing the previous 6 week swim build had been effective vs ineffective (For those who remember, or care: I committed to doing a lot more race pace efforts about two months ago).

This discussion started because the guy who broke the KONA record by .35 seconds per 100M thinks these slight inaccuracies matter. So perhaps we can frame this discussion like this: A real swimmer doesn't rely on a watch because a real swimmer thinks .35 seconds per 100M matters.



laps Distance Time Best Pace 24 600 08:09.6 08:09.6 -- 0 0 00:30.8 22 550 08:22.9 17:03 -- 0 0 00:37.6 4 100 01:14.4 18:55 -- 0 0 00:11.6 4 100 01:14.5 20:21 -- 0 0 00:11.4 4 100 01:14.8 21:47 -- 0 0 00:11.3 4 100 01:14.4 23:13 -- 0 0 00:11.1 4 100 01:15.0 24:39:00 -- 0 0 00:11.4 4 100 01:15.4 26:06:00 -- 0 0 00:10.3 4 100 01:13.6 27:30:00 -- 0 0 00:12.6 4 100 01:14.9 28:58:00 -- 0 0 00:11.2 4 100 01:14.1 30:23:00 -- 0 0 00:20.1 12 300 04:12.1 34:55:00