The triathlon training blog of Phil Barnes

Crooked Swimming Calculator



Our swimmer, is trying to get from point A to point B.

However, our swimmer gets a bit disoriented and swims off-course a bit.

Our swimmer, does look up to navigate a few times, at the cyan coloured dots marked, "Interim Point"

In this example, our swimmer navigates 3 times during the swim, creating 4 Interim segments, of length L.

The swimmer has swum off-course a distance of Y in each segment.

Using good-old pythagorean theorems, we can calculate the angle of mis-swim (theta), and the distance actually swum (L')

Assuming that the swimmer is equally crooked (or using an average value of crookedness) from segment to segment, we can calculate the total amount of extra distance swum.

Armed with this knowledge, we can compute how much extra the swimmer has swum from point A to point B.

If we know what the swimmer's pace is, when not swimming crooked, say in a pool -- we can then calculate a virtual pace -- this would be what the swimmer is timed at for swimming the distance from A to B.

And further, if A to B represents just a portion of the total race distance, we can extrapolate (if it is safe to say that the conditions hold), and we can deduce what the swimmer's final time will be.

We can put all that into a spreadsheet and behold: (you'll need to click it to supersize it)



All in all, it looks like for an average swimmer (2:00 pace per 100m), with a fairly severe degree of crookedness (swimming 10 meters off course every 25 meters) is swimming an extra 116 meters and adding 2 minutes and 19 seconds to his 1500 meter swim time, causing his 2:00 pace to look more like 2:09.

Download the Source Excel File HERE!!!