Pre-requisites : Know how to swim: you can DWS with those fancy orange rescue suits, but your chin and your armpits will never forgive you. Always remember: avoid vicious jellyfish (unless you want your friends to pee on you, or you want to pee on yourself—it really does work to take the sting and poison away, not that we know from experience),...

climbing slanting, positively sloped walls. DWS on positive slopes makes the fall a little uncomfortable. A warm sea, suntanned girls in bikinis cheering your name... all of this requires constant vigilance. Be wise.

Technique of a good fall

Before starting a climb, check the depth of the water (5 meters should be fine for most cases), kill the jellyfishes nearby (just kidding and, anyway, not sure how. Usually they want to get away from you anyway) and make sure there are no shallow hidden reefs below.
Try to fall in a suitable position (i.e. in compliance with the rules of gravity and Euclidian physics): for instance, doggie style should be banished. Though less spectacular, there's nothing better than the "standing" or "sitting on the throne" position.
Don't look at the liquid wall which gets closer as you fall, in order to avoid having your nasal walls collapse. Keep your hands along your body. Stay relaxed and limber on the holds. Don't forget to ask your mates to keep their boats away from the falling area. Falling on the kayak is  the ultimate silly accident, and a bad way to go.

"It's been said that a good mathematician must be lazy, because only then will he find the most elegant way to solve something. That's how I feel about climbing; I'm happiest if I can do something with the minimum amount of effort."
Raphael Slawinski