Yes, DO CROSS YOUR LEGS!

Besides having the feeling of being kicked in the ba*ls you will get a high power enema. It is a VERY violating feeling and uncomfortable. (Yes that is experience talking).

I'd recommend jumping with your shoes on as the impact is substantial over 25 feet. Assume you are going to hit the water at any instant. Most people don't get the timing right the first few times. Stunt men use a bubbler that serves two purpose 1)It helps them to clearly see where the water is below (compensates for depth perception issues) and 2) lowers the surface tension of the water (so the water doesn't impact as much).

In a survival situation, cross the legs, cross the arms and keep ensure your face FOLLOWS your body. I'm not an expert! This is just what I've learned from quarry jumping.

-NIM