There's banana boat and canoeing available at some resorts. No para-sailing - that's probably too risky especially in a marine park where there are snorkellers and divers around.
Don't think you should wear specs with the snorkelling mask, even if you could. Best experience is to use powered masks or some have tried using contacts with masks (see discussion in this forum somewhere - try the forum archives if you can't find it on this main section).
Rgds,
Alex.
Redang Island Rendezvous
www.redang.org