For your own protection. Although sharks don't have a desire for manflesh, they usually have a nibble because they've confused humans for seals or other fun snacks, and attacks usually happen in shallow water. However, this doesn't mean that you're taking any chances. Whenever the opportunity for a quick dip in the sea arrives, you'll make sure that out of all your friends, you're the one closer to the shore. There's no way you're sacrificing yourself when they were the ones who wanted to swim out to the buoy. Last in, first out.
