Again, you will see a wide variety of outfits, from bikinis to burkinis, at Yas Waterworld. Given the activities you will be undertaking and being out in the sun all day, it really is sensible for women to wear something more comfortable. We would suggest a rashie top is a good idea for a waterpark, or at the very least, once-piece bathers that won't come flopping off on any of the rides. If you'll be hanging out by the kiddy pool, a nice kaftan pullover is sensible (you can see a few more ideas over on our Abu Dhabi packing list page) For men, as per the beach, it's better NOT to wear your skimpy speedos and wear shorts. Local lads will probably have T-shirts on as well as knee-length or three-quarter shorts, but tourists will be OK with shorter shorts and topless.