How do you get the crocodile cap in Metal Gear Solid 3

In the Snake Eater not Virtuous Mission, after Rassvet, you'll go directly to Chyornyj Prud, when you get near the end of the room, you'll see a tree with vines that's climbable. Climb, when near tip of branch, hang, go to other end, you'll see another vine under you, fall onto it but GRAB ON, took me a few tries til' I grabbed on to the rope, keep going and you'll see an item box, when picked up you will have aquired the croc cap.