I think swimming is a perfect form of exercise, for all the reasons you mentioned and it's just darn refreshing!
I was able to spend about 2 months earlier this year, swimming each morning and sometimes in the afternoons. Certainly not the laps you mentioned, but enough to make me feel healthier. Sadly for me, I lost the pool access and I'd have to get to the gym to do it. I'm brand new today and haven't made it to the gym yet. But it will come, in time.