I used to race waverunners down at Eastfork lake in my mid and late teens, and one thing you have to learn to keep yourself safe going 70 or so miles and hour over water is how to hit the water should you hit a rouge wave, get bucked off, and eat shit. Actully, its more how NOT to hit the water. Hitting water at speed is actully more dangerous than hitting ground. Water has 3 elements to it that can kill you, while ground only has 2. When you hit ground, its solid, it doesnt give... impact. It also has a high coefficient of friction, it has the ability to just rip your skin off. Water also is very solid when you hit it at speed. Though its a liquid, the amount of time it actully takes to displace your body mass in water, is so slow compared to the velocity of impact, that it makes no difference. Water also has the ability to grab you and twist you around if it has the oppertunity. An arm or a leg that suddenly finds itself below the surface will cause your whole body to whip around very very violently. Lastly, should you hit water and becom unconcious in the wrong postion... you can drowned.
Now the way i was taught to hit the water was pretty simple... face first, on your back if possible, but always with your arms and legs tucked tight. This causes one of two outcomes. If you hit on your back, youll take a nasty shot to the back, but youll skip across the water to a relitively painless stop. Should you hit face down, youll take the brunt of impact to your shoulders... and other than a sore lower back the next day, youll walk away unphased. The one way you should never land, is on your back, feet first. 2 bad things happen. You get a nasty enima, and you get knocked the fuck out. Your feet get snagged and 9 times out of 10 your body gets whipped around so that you do a nasty face plant, knocking you cold.