Compare open water speed to pool speed?

In my experience, if you rule out currents and wind chop the biggest factors are: - (in)ability to sight, that is to plot a course and swim straight - the need to detour around people (sometimes groups of people) in order to pass them The first can be countered by practicing swimming towards things in a lake, without looking up too often. The second is hard to avoid. Seems like sooner or later I always end up having to swim over around or through someone. I suppose you could avoid that by seeding yourself at the very front with the elites, if it's a self-seeded race. Assuming you're fast that is. Edit: to answer the question, it's a safe bet you'll end up going slightly slower than a comparable distance in the pool. For example, if you can swim 1:20 100s in the pool, you might end up with a 1:30 pace in open water. That's what happened to me recently. Even though I know I was swimming at a good pace, I also know I swam more yardage than originally intended! I was surprised to find that I swam faster in a recent open water race than the same distance in a pool. But the race was timed to have swimmers get a tide assist, and also going from fresh water to salt water, I had more buoyancy. I would have thought these things would have been offset by the chop and my increasing seasickness, but the latter, I think, made me more and more reluctant to stop for food, which also might have taken some time off. (When I swam the same distance in training, I did stop periodically for gels and water.) But hard to say in a lake since it's going to be fresh water. But no turns, so that should help!

In my experience, if you rule out currents and wind chop the biggest factors are: - (in)ability to sight, that is to plot a course and swim straight - the need to detour around people (sometimes groups of people) in order to pass them The first can be countered by practicing swimming towards things in a lake, without looking up too often. The second is hard to avoid. Seems like sooner or later I always end up having to swim over around or through someone. I suppose you could avoid that by seeding yourself at the very front with the elites, if it's a self-seeded race. Assuming you're fast that is. Edit: to answer the question, it's a safe bet you'll end up going slightly slower than a comparable distance in the pool. For example, if you can swim 1:20 100s in the pool, you might end up with a 1:30 pace in open water. That's what happened to me recently. Even though I know I was swimming at a good pace, I also know I swam more yardage than originally intended! I was surprised to find that I swam faster in a recent open water race than the same distance in a pool. But the race was timed to have swimmers get a tide assist, and also going from fresh water to salt water, I had more buoyancy. I would have thought these things would have been offset by the chop and my increasing seasickness, but the latter, I think, made me more and more reluctant to stop for food, which also might have taken some time off. (When I swam the same distance in training, I did stop periodically for gels and water.) But hard to say in a lake since it's going to be fresh water. But no turns, so that should help!