We were sailing along normally, quite bored, when suddenly I saw a splash. I looked up and I saw another splash. Then we saw a dolphin do a huge jump out of the water! We quickly grabbed our life jackets and harnesses, and ran up to the foredeck. Only to find, about fifty dolphins swarming underneath and around us. We kept on watching them and in the distance we saw lots more dolphins, in three's doing huge jumps. It was really, really, really exciting and they were very pretty. They were zooming along, about the same speed as us ( About 4 or 5 knots) and it looked as though it took almost no effort. They kept on peeling off then gliding back to the boat. George and Jack quickly went below and came back with the camera's. Strangely there were loads of birds flying above, perhaps they were all fishing together? (Although we didn't catch any fish...) They stayed with us for a good quarter of an hour, but eventual left. Except for one who stayed under us for another 5 minutes, before he to left.