Here in Florida there's no such thing as a private natural lake. By law, there has to be public access. I don't think that acreage matters. Now, alot of the lakes "look" private because of developement but if you'll check county survey maps, the access can be located. Sometimes they are hard to find because the owner next to the access has sodded the area and mows the grass and it looks all prim and propper. Worse yet, someone put up a fence thinking that it was his in the first place.
I met a gentleman years ago that was mowing a lake access so it blended right into his property. There was a posted boyscout camp on the other side of the lake that was posted to trespassers so the only way to hunt the water area was by canoe. Should have seen the look on his face when I carried a canoe through "his yard". I showed him the map and explained his error, he eventually came around but I could tell he wasn't too thrilled about the idea. I told him it would be our little secret but I would be back from time to time to use the access. He agreed and was very cordial whenever I returned.
Would you ask an owners permission to fish, from a boat, around and under his dock? I have always asked this question..... If the lakes are public property, what gives homeowners the right to put up docks on public property? Better yet, If I climb up on a dock, built on public property, why is that considered trespassing? Interesting dilema if you consider it.
I would scuba and hunt under these docks as much as I wanted to, just be respectful if they are being used at the time, and leave the bottom as you found it when you left. Oh, and if you find anything under it that belongs to the dock owner like dive masks, snorkels or anything else used by kids that are out of reach, toss it on the dock, you'll probably at least be tolerated. One other thing, pick up ALL garbage, that way if you are confronted by an angry owner, you can show him the garbage you collected from under his dock. He may be appreciative and change his attitude. Good luck and go get 'em.
therick