If you're looking to join, ask yourself if you want to be the first (Marines) to go into a combat zone and face the greatest threat level while giving the enemy holy hell, or be the second to go in (Army), perhaps with a lower risk to some degree, but miss the excitement of not being those who did go in first and stung the hardest.
***RESPONSE*** to tyler31093
Perhaps you are referring to Drownproofing, a technique developed by (long since deceased) Coach Fred Lanoue at GA Tech. And indeed, various methods of being tied up and in water while not drowning are taught. The purpose is to simulate being in water without drowning after having one or more limbs made useless due to an accident or injury.
And no, the Corp does not let its Marines drown during these exercises--this would have to be an anti-military myth. What would be the logic in that? It costs much money to train a Marine; they are not going to let men, their assests, drown when they are teaching drownproofing.
I took Fred Lanoue's (not from him, though...I'm not that old) drownproofing course...best thing I ever did for myself. Being in water over my head, I would die of thirst (if salt water) or hunger before I'd drown now. Look at: http://en.wikipedia.org/wiki/Drownproofing