I will certainly echo what others have said here. I would get the replacement done sooner than later. I had multiple injections in my hip for a couple of years prior to getting a replacement. Felt great afterward and regret not doing the replacement earlier and avoiding the injections. Was back to activity quite quickly with rigorous physical therapy. Regarding diving: Absolutely no problem, however some dive boats have a tree ladder in the center of the boat which requires you to throw your leg over to get back on. It was not an issue for me but could be if you lose some flexibility-another reason to take the physical therapy seriously.