I'm just curious if any of other fellow asthma sufferers have this
problem...

I like to swim, but until recently (been trying to overcome this) I
found myself a little nervous around water over my head.  I never
really realized how unusual this was till one day when I swam with my
younger cousin (who, btw doesn't have asthma) and her father, and
noticed how they had no problem with diving under water, and swimming
around in the deep area.

Now, I know how to swim (probably not do all the kicking and hand
movements right, but i can get from one end to the other without
touching the floor if i need to).  But I suddenly how I've never liked
being underwater for too long, and how (when I was younger esp) I'd
panic when I jumped into and found it was over my head.,  

I'm not sure, but I'm guessing having asthma is the cause of the
apprehension, that is, I don't like being in situation where I can't
breathe freely.

I've been trying to overcome this though, I'm okay with swimming (or
even just "walking") around in the deeper area of our local pool
(still not too good at jump INTO deep water though, always feels like
it taking too long for me to surface.  And it seems like whenever I go
under, it always takes me a good minute or two to get my breath back
to "normal" and I have to fight the urge to take a puff on my inhaler
(even though I just took one before going under water.)

I'm curious, is this a normal occurence among asthma suffers?

Also, any tips on how I can expand my lung capcity?  (Or is just a
matter of, going under, see long you can stay there, go up, repeat
till you get better?)

Thanks