Dolphins are highly efficient and powerful marine mammals. Their graceful movements often mask the sheer power and speed they possess while navigating their aquatic environment. Understanding dolphin locomotion requires looking beyond a single number, focusing instead on the impressive range of speeds they can achieve when necessary.
The Difference Between Cruising and Burst Speed
A dolphin’s speed is divided into two distinct categories: cruising speed and burst speed. Cruising speed is the velocity an animal can maintain comfortably for extended periods, typically falling between 8 and 10 miles per hour (MPH) for many species. A common bottlenose dolphin, for instance, often averages a sustained speed between 3.3 and 7.0 MPH. When hunting prey, escaping a predator, or engaging in playful leaps, dolphins deploy their burst speed. These short-duration sprints can launch the animals to speeds far exceeding their average, approaching 37 MPH for some species.
Biological Adaptations for High Velocity
The remarkable speed capabilities of dolphins are rooted in their highly specialized biological and physical structure. Their bodies exhibit a fusiform, or torpedo-like, shape which significantly reduces drag and allows for energy-efficient movement. A specialized skin structure also minimizes friction by helping maintain laminar flow, where water moves smoothly over the body rather than creating turbulent eddies that would slow the animal down. Dolphins continuously shed the outermost layer of their skin, keeping the surface remarkably smooth. The primary engine for propulsion lies in the powerful tail and flukes, where large muscles in the tail stock (peduncle) deliver force in an efficient vertical motion, generating thrust on both the upward and downward strokes.
How Different Species Compare
The term “dolphin speed” is not uniform across the nearly 40 species within the oceanic dolphin family, as size and environment influence maximum velocity. The common dolphin (Delphinus delphis) is typically cited as the fastest, reaching maximum burst speeds of up to 37 MPH, while the Orca (Orcinus orca), the largest member of the family, is capable of short bursts approaching 34 to 35 MPH. The familiar bottlenose dolphin (Tursiops truncatus) is generally slower than its open-ocean relatives, with a top speed often recorded between 18 and 22 MPH. Another particularly fast small cetacean is the Dall’s porpoise, which has been clocked at speeds up to 34 MPH. Scientists gather this speed data through various methods, including observations from tracking alongside research vessels, though bow-riding complicates accurate measurement of their self-propelled speed.