Professional coutesy

One weekend, a doctor, a priest and a lawyer were out in a fishing boat. Their motor had broken down and one of the oars had drifted off. Just as the doctor was about to dive in to retrieve the oar, the boat was surrounded by sharks.
I can--t go now, the doctor said. If someone gets bitten, you--ll need my services.
I can--t go either, said the priest. If the doctor fails, I--ll need to give last rites.
Fine, said the lawyer. I--ll get it. He dived in, the sharks moved, and he retrieved the oar and climbed back into the boat.
The doctor and priest looked flabbergasted. The lawyer just smiled and said, Professional courtesy.