Puerto Galera/Sabang
Not sure if you already decided where to go to, but if you have problems with your knee, I don't think I can recommend Asia Divers in Puerto Galera. Unlike the other shops they have a dive platform that they tie their boats to, so the boat quite often rocks left to right while you have to enter/exit, and sometimes it would be rather "jumping" to get off the boat onto the platform.
I found it much easier and safer to exit/enter the boats that were just sitting in the shallows at the beach.
As for diving, you have sites with more current and sites with less, also depending on tides and moon.
For example, we went to Verde Island few days ago where beforehand everybody warned about strong currents, but it turned out we had barely any at all.
I was on some dives where we had quite some current, and to see something specific we sometimes had to go a bit against the current, too, but you could just skip those dives. We also always had the option to hand our gear up before getting onto the boat out of the water, and on the smaller bangka that was actually common practice.
I have to say though, for the drift dives I often wished for a bit better visibility.