I'm friends with a local dad. I take DS2 swimming in the afternoons sometimes. The dad has suggested that he and his DD tag along sometime. (We do things in the afternoon pretty often, the four of us, or the six of us when we have our older kids with us.)
Frankly, I find swimming with a female friend slightly stressful and weird. I don't exactly live in a burka or anything, but swimsuits are frankly too revealing imo and I just really don't feel comfortable with the idea.
(And yes, I do sometimes run into dads I know at the pool, and I'm friendly and nice, and it's fine really. But I wouldn't set out to run into a bloke there!)