I have just come back from another dolphin-watching trip in Bali and I was amazed at the number of dolphins that were swimming around the boat as we were travelling. I could see them feeding as they were behind the boat, and their speed and acrobatics were amazing.
Dolphins use the waves from boats to increase their swimming distance and speed. They can also feed on fish swept up by the ship’s waves. Dolphins are curious about boats and the people on them and often swim in front of them.
On the dolphin-watching trip, I saw some large pods of dolphins and even managed to see some jumping about an arm’s length from me.
Why Do Dolphins Swim with Boats?
Dolphins are often seen swimming alongside ships at sea. Dolphins have several reasons for doing this. Dolphins are naturally curious creatures and are attracted to the movement and sounds of boats. Swimming alongside boats allows them to investigate and interact with the boats and us. Riding the bow wave created by the boat is an energy-efficient way for dolphins to move through the water, and can be a way for them to get food.
Dolphins use echolocation. If you want to find out more, I have written an article here.
Food
Dolphins often see a boat full of people as an excellent opportunity for food. Although not so common anymore, people throw fish overboard to attract dolphins.
A fishing vessel with packed nets is also an excellent food source for a hungry dolphin. For hundreds of years, these mammals have been swimming beside ships, and it seems that they must have learned from experience that where there are humans, there is also a good chance of food.
Fish also get swept up by the boat waves and I saw plenty of flying fish moving out of the way of the boat, with some being caught by the dolphins alongside the boat.
Ever wondered what senses dolphins have? If so, find out here.
Greater Distance
The wake created by boats helps dolphins move swiftly through the water with minimal effort. Dolphins can ride in the boat’s wake, covering longer distances without expending extra energy.
When the wake created by a particular ship is high, dolphins can coast along behind a boat quickly and easily, moving them from one location to the next.
This behavior is not only energy-efficient but also a testament to the remarkable adaptability of dolphins in utilizing their environment to their advantage.
How do dolphins swim? Find out here.
Showing Off
Dolphins typically live and travel in groups ranging from 2 to 40 dolphins. Pods as large as several hundred members have also been seen. These groups are commonly regarded as herds, schools, or superpods.
In some cases, these large groups have been known to include more than one species interacting. The species that usually interact in this multi-species group are Spinner dolphins and Spotted dolphins.
These large pods can often be seen next to a boat, showing off their skills to other species. Both species will try to outdo the other, showing their jumps, flips, and tricks.
The grouping works exceptionally well for Spinner dolphins and Spotted dolphins because their feeding habits are different, making it possible for them to travel together without having to compete for food.
If you want to know why dolphins jump out of the water, I have written an article you can find here.
Fun
Dolphins are renowned for their playful nature, and it appears that a significant portion of their behaviors is driven by sheer enjoyment. From darting through the water at remarkable speeds to engaging in acrobatic flips and jumps, these intelligent marine mammals often display behaviors that seem to be driven by the simple pleasure of the experience.
When it comes to riding the wake produced by boats, it’s not just a matter of efficiency; it’s also about the exhilaration of speed. For dolphins, the wake generated by boats serves as a thrilling speed booster, allowing them to experience the rush of swiftly gliding through the water.
This playfulness and zest for life are some of the endearing qualities that continue to captivate and fascinate observers of these remarkable creatures.
Curiosity
As a result of their high intellectual capacity, dolphins are more curious than many other animals. Dolphins will approach unfamiliar objects and creatures to learn about them unless they have previously had a bad interaction.
The wake generated by a boat creates a strong disturbance on the water’s surface that dolphins can sense and want to investigate. Dolphins will often do this by leaping out of the water, appearing to play in the wake.
Dolphins also seem to have individual interests. While some dolphins would come close to our boat, others wouldn’t. There are reasons why dolphins might find a ship’s company appealing or not, depending on the type of vessel, its passengers, and the dolphin’s mood.
Dolphins are usually found in offshore & deeper waters, where very few boats go. They are curious about any newcomers in their habitat, so dolphins will swim along with large and small ships.
Dolphins are intrigued by boats’ noise, motion, and movements and will often follow them for a short while if a ship crosses their pod’s direction.
Want to know how dolphins breastfeed underwater? Find out here.
Faster
Dolphins can swim at speeds ranging from 3 to 6 mph, while the fastest dolphin species can reach up to a maximum speed of 20 mph. Utilizing a ship’s wake allows them to swim even faster with minimal additional effort.
Dolphins often swim alongside large ships because the waves generated by these vessels enable them to swim faster. This occurs because the bow (front) of the ship pushes the water aside as the boat moves forward, creating a “wave or wake in the water that dolphins can utilize to increase their swimming speed.
Dolphins following a boat are continually being pushed toward the surface and propelled forward at the ship’s speed. This allows the dolphin an easier way to move forward. Dolphins can swim alongside the boat without having to spend much energy.
Why Do Dolphins Swim in Front and Behind Boats?
A look at a dolphin’s personality can explain the behavior of swimming in front and behind boats. When they notice an unfamiliar object moving along the surface of the water, dolphins get curious. They approach ships to determine what is happening and if they are a threat.
Dolphins have complex communication with their environment, which explains the happiness they derive from hearing humans clap and cheer for them from the boats.
Dolphins acknowledge and react to adoring crowds. They are generally eager to perform for an audience. Dolphins seem to get pleasure from surfing through the waves next to a boat. They will jump in the air, seemingly for the amusement of people on board.
Did you know there are 16 species of dolphins in North America? Find out what they are here.
Do Dolphins Get Struck by Boats?
Occasionally, dolphins do get hit by boats. The propellers on a ship can be responsible for hundreds, if not thousands of dolphin deaths every year.
Most dolphins hit by vessels were either young calves or dolphins not fully grown. The adults that were struck were generally mothers with their young.
Young dolphins are slow swimmers. Another reason is they could not dive as well as they do not have fully developed lungs.
Bottlenose dolphins are found closer to the coast. This makes them more liable to a hit from a boat or ship. The probability of vessels striking marine mammals decreases when speed is reduced, and wildlife organizations have been instrumental in campaigning for slower speeds.
Dolphins use sound to echolocate, and certain boats and vessels can be dangerous. Jet skis are particularly troublesome, as they are quieter than most other boats. This makes them even harder for marine mammals to detect and avoid.
However, two of the biggest threats to dolphins are entanglement in fishing gear and nets and pollution. Sometimes, dolphins follow the same fish species that fishing boats are hunting and may get accidentally caught in their nets.
The ocean is greatly affected by pollution created by us. Pollution has been a severe threat to these aquatic mammals causing diseases and difficulty finding food.
References And Further Reading
Whales, dolphins, and porpoises – Carwardine, M.
Mark Carwardine’s Guide to Whale Watching in North America – Carwardine, M.
Whales, dolphins, and seals – A field guide to the world’s marine mammals – Hadoram Shirihai,
The illustrated Encyclopedia of Whales and Dolphins – T. Martin
Walker’s mammals of the world – R.M. Nowak and E.P. Walker
The Smithsonian book of North American mammals – D.E. Wilson
Bryan Harding is a member of the American Society of Mammalogists and a member of the American Birding Association. Bryan is especially fond of mammals and has studied and worked with them around the world. Bryan serves as owner, writer, and publisher of North American Nature.