There is a swim test for PADI OW but when my wife took it it was her choice which stroke she wanted to do to cover the distance.
I took it in 71 before the course was broken up into OW, AOW, wreck, nav, deep, rescue, firstaid, CPR marine ID and all of the others courses that would now make up Master Diver. Besides the different strokes there was a long drown proofing test. I’m not sure if that is still included.