As a former sailor in the U.S. Navy I encountered many dolphins on various cruises in different parts of the world. The most interesting time however was in Exmouth, Western Australia about 1976. We had a small group of Christians at the beach doing a water baptism. The pastor had a guy waist deep in the water getting ready to plunge him under & was sharing some scriptures with a group of us on the beach. While he was talking we all noticed a couple of fins headed towards them from about 30 yards away. The pastor was oblivious to what was happening while we were all in a panic [we had a large population of sharks in the area]. The fins kept coming closer and we all got more animated until just as the candidate was dropped in the water 2 dolphins swam right up to them and broke water. It was a great relief to see their friendly forms instead of their nemesis. It was just another curious encounter for them but a lively baptism service for us.