A doctor a rabbi and a lawyer are adrift at sea in a tiny life raft for going on 4 days when they spot a small island off in the distance.
They spot an island off in the distance and, as the current draws them closer they realize that they're going to miss it unless somebody gets out and swims. And the waters are shark infested, of course. (almost goes without saying in these stories.)
The doctor and the rabbi have become solid friends by this time, discussing history and philosophy together to take their minds off of their situation. And so they argued over which one should take the risk. The doctor, who is an atheist, cites his hypocratic oath and the rabbi claims his assurance of going to heaven as reasons why they each should be the one to jump in the water.
The lawyer, who had stopped talking to his boat mates a day earlier, said nothing. He just pulled the lead over his shoulder, jumped overboard and started swimming. The other two were stunned into silence, having judged the fellow to be an uncaring, self serving, ruthless waste of salt. Moreover, as they watched in amazement, the sharks parted the way, allowing the little boat to pass safely to that little island shore.
After some recovery time, they asked the lawyer how he had done it.
"Professional courtesy" was all he said before initiating discussion of book rights.