This September I swam more in a pool then in the ocean! Having a month-ticket to a nice neighboring pool makes it easier, and there was too much seaweed along the coast this year after the first hot weeks of Fall.
In the pool I used to make around 60 short lengths (25 yards) first, but then my friend pro-swimmer suggested I should do 66 (one mile, or 1650 yards, or 1.5 kilometres), and I switch to a swimmer's mile a day. I turn like I do in open waters, barely touching the walls and it takes me the whole 45 minutes of non-stop breaststroke to finish :) You may laugh about it, but for somebody whose main sport in youth was piano I am doing pretty nicely.
I am looking forward to double the distance if I have a chance to continue in this open air heated pool (~80F) for months, but I am not sure that staying in the chlorinated water for one and a half hours will be very pleasant, in the ocean it is no problem till 2-2.5 hours, but in the Pacific I get cold by the end.
A few days ago I bought a waterproof solar training watch with a timer and 120 laps counting by pressing a button, so now I don't need to keep numbers in my head and can go into a happy trance :)