Physics momentum help? this question should be easy but i cant get it. 10 pts to best answer?

A 53-kg woman contestant on a reality television show is at rest at the south end of a horizontal 149-kg raft that is floating in crocodile-infested waters. She and the raft are initially at rest. She needs to jump from the raft to a platform that is several meters off the north end of the raft. She takes a running start. When she reaches the north end of the raft she is running at 4.1 m/s relative to the raft. At that instant, what is her velocity relative to the water?