Sailfish are considered the Usain Bolt of the seas. Their impressive agility and striking appearance have captivated ocean lovers and sports fishers. Known for reaching up to 62 miles per hour and changing colour in the process, these magnificent creatures know a thing or two about multitasking. Did we mention they're also remarkably acrobatic? So, whether you dream of trying to keep pace with them as they hunt bait balls or want to learn more about these sword-swashing fish, read on for our favourite sailfish facts.

A sailfish showing off it's impressive dorsal fin and swimming close to the surface

Spot the sailfish

Sailfish are distinctive due to their sail-like dorsal fin, streamlined body and long pointed bill that looks like a sword. They are blue or grey in colour, although this can change when they're on the move. Their bodies are built for fast, agile movement.


Sailfish get their name from their most distinctive feature: the large, sail-like dorsal fin. This prominent fin, which can be as tall as the fish's body, resembles a fully extended sail, can be raised or lowered, and is often displayed when the sailfish is excited or hunting.

underwater photo of a sailfish circling a school of small fish

Sail away

Sailfish raise and lower their sails for various reasons. When hunting schools of fish, the raised dorsal fin can help herd small fish and act as a visual barrier, confusing the prey and making them easier to catch. It's also raised to make them look larger than they are in the hope of intimidating predators or rivals. When sailfish need to pick up speed, they lower the fin to streamline their bodies and reduce drag. Some scientists believe that raising the dorsal fin can also be a way to regulate their temperature. But we're still waiting on solid proof of this sailfish fact.

Sleek speedsters

All these characteristics and anatomical attributes play a role in the well-known sailfish fact that they are considered the fastest fish in the sea and can reach top speeds of 62 miles per hour. It should be mentioned that these speeds are widely debated, but regardless, they're fast.

two sailfish swimming in open water, one closer to the camera and the other slightly further back

Sport fishing

Their speed, magnificent appearance and size make them a trophy item in many sport fishing communities. In fact, the largest sailfish ever caught was 11ft long and weighed 220lb.

Colour changing artists

One of our favourite sailfish facts is their ability to change colour, often turning a vibrant blue with stripes when excited or hunting. When hunting, sailfish change colour to communicate their intentions with their hunting herd (as you can imagine, due to their speed and long bill, a collision with a fellow sailfish could be fatal) and transform into a vibrant blue with stripes. This sudden colour change can confuse and disorient their prey, making catching them easier.

Two sailfish swimming underwater close to each other with one slightly blocking the other from view

Flirting and courting

Another way sailfish use their colour-changing abilities is to court a potential mate. During the mating season, males turn a bright hue to attract a female, and, to seal the deal, raise their dorsal fins to show off their impressive size. If successful, the sailfish will engage in a courtship dance where both sexes swim closely together, sometimes in circles or figure-of-eight patterns.

Millions of eggs

If the courting has gone according to plan, the female releases eggs into the water while the male fertilises them externally. Females can lay many eggs - four and a half million, in fact. Once the spawning has happened, the parent fish leave the eggs to develop and fend for themselves. But fortunately, these little eggs don't have to wait long and typically hatch within 36 hours of being laid. Talk about speedy…

Underwater photo showing a sailfish with blue stripes herding a baitball of small fish

Swimming with sailfish

Swimming with sailfish is often featured on bucket lists. And one of the best places to spot them is during the sardine runs off the coast of Isla Mujeres near Cancun, Mexico. From December to March, these waters attract sailfish, which feed on sardines, so divers have double the excitement of seeing the famous shimmering sardine run and witnessing sailfish in their hunting prime.

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