At the end of the carrier, in stead of killing all the guys on top of it, just shoot the gunner on the helicopter and jump into the water. Swim low and make sure you got the gunner (you will see him fall of the helicopter). If you didn't, he will just shoot you while your in the water. Than swim to where the carrier was cracked, shoot off the chains of the raft boat, (look above you to find it) and swim away. Very, very easy.
Submitted by little tortia