At high speeds dolphins save energy by leaping

@article{Au1980AtHS,
  title={At high speeds dolphins save energy by leaping},
  author={D. Au and Donna Weihs},
  journal={Nature},
  year={1980},
  volume={284},
  pages={548-550}
}
An observer may wonder whether a school of ‘running’ dolphins, consisting of numerous, wildly splashing individuals, is using the most efficient mode of locomotion, because splashing wastes energy. Dolphins exhibit at least three modes of swimming. In leisurely, unhurried motion, they break the surface briefly and gently, often showing little more than the blowhole. At a faster, ‘cruising’ speed, frequently at 3–3.5 ms−1 (6–7 knots), the animals are seen swimming primarily just beneath the… 
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References

SHOWING 1-2 OF 2 REFERENCES
Hydrodynamic Performance of Porpoises (Stenella attenuata)
TLDR
Two specimens of Stenella attenuata, trained to chase a winchtowed lure, reached a top speed of 11.03 meters per second (21.4 knots) in 2.0 seconds, and the maximum power output per unit body weight was 50 percent greater than for human athletes.