Labadee, Haiti -- water park

I'm looking at excursions through RC. If we're wandering around the area after the teen kids and dh has gone on the zip line and we want something like a floating beach mat or the kids want to go to Arawak Water Park. Can we sign up while we're there, or do we have to have preplanned/committed to this?

You can get both matts and waterpark passes during the day. Matts are very plentiful. You may have to wait a bit for the waterpark if there are already many people using it but it would not be a long wait.