How do you beat titanic island on poptropica?

The best way is to keep to the front of the boat, and remember the sequence of obstacles: stalactite falling, weird green floaty thing, mutated alligator. To avoid these, jump, duck, jump. So, when the obstacles are in range, jump above the stalactite, duck from the floaty thing, and jump above the alligator. Jump, duck, jump, jump, duck, jump, jump, duck, jump... just remember to keep at the front of the boat.