Did you read and sign the waiver obsolving the dive club of liabilites?
If yes, then I would would have to say "no", they aren't liable.
Ask our "resident" legal beagel... Greg. But then, lawyers will always
tell you that you have a case.. just pony up the money.

It's complex.  Unlike in the US, a waiver up here should provide you
with some legal protection.  If you have a waiver, in theory, your but
is covered.  Unless they can show that you were negligent, which isn't
necessarily too hard for them to do.  I know this is expensive, but it
is in your best interest to consult a lawyer (preferably one with a
sports/leisure related background).  He/she can draw up a proper waiver,
as well as give you a better idea of what your potential liabilities
are, and how else you can cover your a.s.

And just aside, a waiver is only one layer of protection, and in no way
represents complete legal protection.  I've run several youth camps in
which we've required waivers for some/all activities.  But on top of
that we always carry liability insurance, and sometimes have additional
insurance on top of that (i.e. to cover damaged equipment, etc).  If you
truly want to be legally prepared you need more then just a waiver -
liability insurance is another layer of protection you may want to seek out.

I don't think I can stress the "talk to a lawyer" bit enough - a single
consultation and production of waiver will not be cheap, but it'll be a
hell of a lot cheaper then if you use an incomplete waiver and get sued.
 Plus the lawyer should be able to give you a better idea of what
you'll need in terms of insurance, provide you with pointers on how to
cover your a.s, and point out additional legal problems you may encounter.

Bryan