The swimming speed of crocodiles varies from 24 to 35 kilometers per hour. The fastest is the Nile crocodile, which can swim, on average, between 30 and 35 kilometers per hour.
Crocodiles, despite being agile underwater, are not strong swimmers. Like their cousins, the alligators, the crocodile can swim fast in short bursts, but they cannot sustain higher speeds like fish.
Can a Human Outswim a Crocodile?
No, a human being cannot outswim a crocodile. The fastest human speed for swimming is 2.29 meters per second, or 8.2km/h. Crocodiles can swim more than 4x as fast, reaching speeds of 35km/h.
Here is a comparison:
- Crocodile – 35 kilometers per hour
- Human – 8.2 kilometers per hour
The crocodile is four times faster than a human being, so there is no way a human can outswim a crocodile.
Once a crocodile hunts a swimmer, that swimmer is in grave danger. A human may be able to ward off a crocodile in such an attack, but it can only happen with luck.
Read More: Could a Human Outrun a Crocodile on Land?
How do Crocodiles Swim?
The crocodile’s main tool for swimming is its tail. The limbs are small, and they do not help that much to propel themselves underwater.
Since the limbs are not significant to swimming, the crocodile folds them to its side when swimming. Then, it undulates its entire body from head to tail to move. A crocodile uses its limb as a stabilizer. Its feet have webbing.
Underwater, the crocodile has three types of movement. These are swimming, floating, and diving.
When they swim, they place their limbs to their sides. Then, they move their bodies from side to side, using their tails to propel themselves forward. This movement looks like a wave.
While floating, their bodies are almost vertical underwater, with only their heads sticking out. However, they can also do a horizontal float, and this is the kind of float people see where the back of the crocodile is also visible above the water.
The crocodile goes deep into the river or seabed in a dive and then walks. Before it goes on a dive, it exhales air from its lungs to reduce its buoyancy. Crocodiles can hold their breath for an hour before going back up to breathe.
Read Also: Do Crocodile Eat Rocks?
Will Crocodiles Attack Humans Underwater?
Crocodiles may attack human beings and other animals underwater. Crocodile attacks on humans are common, and there is even an organization set up to track crocodile attacks across the world called CrocBITE.
The global estimate is that 1,000 human beings die from crocodiles attacks each year. In many cases, the two species that typically prey on humans are the Nile and Saltwater crocodile. These two are responsible for most fatal and non-fatal attacks.
While many crocodiles attack humans as prey, it is not the case all the time. For example, the mugger crocodile in India is vicious for attacking humans, but they do this for territorial reasons.
Crocodiles are somewhat defensive but not predatory when humans are involved. They do not eat the humans they attacked. Crocodiles will also attack humans that they perceive as a threat, especially if they are protecting their nests.
There is a pervasive myth saying that crocodiles will not attack underwater. It is because crocodiles have a valve in their mouths. This valve closes when they are underwater, so they do not swallow it when they are under.
Because of this valve and how it works, some people think crocodiles cannot open their mouths in a dive. This premise is wrong.
Crocodiles can open their mouths and shut their jaws underwater. They can even do a roll. However, they cannot swallow underwater. They need to be on land or shallow water to swallow. If they swallow underwater, they may drown.
Crocodiles depend on the land for hunting, eating, breeding, hibernating, laying their eggs, and sleeping.
Read More: Are Crocodiles Considered Dinosaurs?
Are Crocodiles Faster in Water than on Land?
On land, a crocodile can run at 17 kilometers per hour, whereas in the water crocodiles can swim at up to 35km/h. Crocodiles are about twice as fast in the water as they are on land.
Related Post: How Fast can Crocodiles Run on Land
Can Crocodiles Breathe Underwater?
Crocodiles cannot breathe underwater. Unlike fish and some amphibians, crocodiles have air-breathing lungs and need to surface to breathe.
In a dive or swim, a crocodile holds its breath. Like humans, its only reserve oxygen is what it has in its lungs. As such, the smaller the croc, the less time it can spend underwater.
Typically, a croc can hold its breath for 15 minutes. In some situations, like if it is under duress, it can stay in there for 30 minutes. In extreme situations, the crocodile can stay underwater for two hours. In this situation, the crocodile’s heartbeat reduces to only two or three per minute.
All in all, the crocodile reduces its oxygen consumption. It only sends oxygen to important parts of its body. It is a feat that human beings cannot do.
When a crocodile dives, though, it has to expel a lot of air from its lungs. What this means is that it has less oxygen to use in a dive.
Summary: How Fast Can Crocodiles Swim?
Crocodiles are fast swimmers compared to humans. The fastest is the Nile crocodile, with swimming speeds of 30 to 35 kilometers per hour.
Crocodiles can and would attack humans underwater. Not all crocodiles do this to eat—some are territorial. It is not true that a crocodile cannot open its mouth underwater. They will attack if they are hungry or under threat.
Stuart is the editor of Fauna Facts. He edits our writers’ work as well as contributing his own content. Stuart is passionate about sustainable farming and animal welfare and has written extensively on cows and geese for the site.