We went to Acapulco on a land trip a few years ago......when we snorkeled the only fish we saw was the rubber one the guide held up......it was a horrible feeling to be in the water there and realize we were the only live things in the water.....lots of trash floating and not a sea bird in sight......I couldn't wait to get out of the water once we realized it was bad. Not sure if the whole area is this way but that was our experience.
I don't think you want your skin to touch the water anywhere in Acapulco Harbor. It may just be the most polluted body of water in the world. Sewer systems from all the hotels empty directly into the harbor.