Student or Learner
"Swimming enclosures afford a high degree of protection, however, they are stinger resistant not stinger proof. To avoid Irukandji stings check with Lifeguard/Lifesavers."
I assume that proof means more than resistant, but don't know how exactly. It's seems to be the same problem with watches... for me :).
a water proof watch
a water resistant watch
Where's the difference?
You can wear your water-resistant watch in the rain, but not swimming.
You can wear your water-resistant jacket in a light drizzle, but not in a hurricane.
Something that is "resistant" resists (fights off) for a little while, but it's not a complete guarantee. Something that is "proof" will be protected from it completely.
(For the record, I think that anyone who says something is "foolproof" underestimates the ingenuity of the fool. It's more like "fool-resistant.")
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.