> However!  I can now only just manage one chin-up! :-)

I've never found the "chin up" to be a good mark for
measuring much and even less useful for scuba.

Rather, I'll use an overhead bar, wrap my legs around
the bench and use the pull down (same movement as chin
up, but there are weights moving, not your body).  At
least you can do this with less weight than you weigh.
This exercise gives you a better range of motion as well.
The same "machine" setup (probably less weight) can be
used for tricep extension, wrist work, etc.

I'm going to hit the water, maybe this weekend and get
a few times... Then I'm going to put together the versa
trainer, work on it a few weeks then try again.  I'm
curious if these workouts will help without the daily
(or even 2-3x/week) swimming.