How fast can Dolphins swim?

The Dolphin’s fast cruising speed (a travelling speed they can maintain for quite a while) is about 11 – 12.5 km/hr. They can reach speeds of up to 16.5 km/hr while travelling in this fashion. When they move faster, they will start jumping clear of the water (porpoising). They are actually saving energy by jumping. When chased by a speedboat, Dolphins have been clocked at speeds of 26.3 km/hr, which they maintained for about 1500 meters, leaping constantly. Energetic studies have shown that the most efficient traveling speed for Dolphins is between 6.0 – 8.2 km/hr. There have been reports of Dolphins traveling at much higher speeds, but these refer to Dolphins being pushed along by the bow wave of a speeding boat – they were getting a free ride. It is possible that Dolphins can reach speeds over 15 knots during very short bursts (like in preparation for a high jump), but they can’t maintain that speed.