Yea the blue ringed one is a particularly nasty critter, very poisonous!

I dived on the barrier reef 2 or 3 years ago, very disappointing!

Some of the best diving is the red sea in Egypt, we've [Wife] dived mostly in the Caribbean and Florida keys.

If you want to do it, go for it, it's really not that difficult and you don't need to be a good swimmer, there's virtually no swimming involved.
There is a swim test but it's easy if you do the PADI course, BSAC is a lot harder, I wouldn't have passed the BSAC swim test but I did pass the PADI one.

Injustice will be avenged.
Cofiwch Dryweryn.