Like everyone said, those are awesome finds!!! I really need to get a diving certification one day. It must be really cool to be able to dive..... and find bottles on top of that!!! Really cool man.
Nice digs but I would say definately not a pontil on the bottle in question. While it looks like one in the photo it looks rounded and not rough. I'd say it's part of the mold. The bottle itself looks like a 1910-20 era shoe polish, maybe even a little later.