The Fastest Fish in the Ocean Can Swim at Nearly 70 MPH

By: Clarissa Mitton  | 
A large fish with a spear-like nose turns toward a school of smaller fish swimming away
The sailfish (right) will have no trouble chasing down the Brazilian sardines (left). Stuart Westmorland / Getty Images
Key Takeaways
  • The sailfish is the fastest fish in the ocean, reaching speeds up to 68 mph (109 km/h), thanks to its streamlined body and powerful fins.
  • Swordfish, wahoo and Atlantic bluefin tuna are also among the fastest fish, with speeds ranging from 44 to 60 mph (71 to 97 km/h), each having specialized adaptations for high-speed swimming.
  • Mako sharks and blue sharks are the fastest sharks, with speeds of 46 mph (74 km/h) and 43 mph (69 km/h), respectively, relying on streamlined bodies and powerful tails for propulsion.

While there are tons of fish in the sea, only a few hold the title of the fastest fish in the ocean. You might wonder how the fastest fish swim at such high speeds.

The key to a fish's speed is a streamlined shape. It's usually fish with a pointed snout and broad, propulsive tail that are able to move through the open with minimal resistance.


So, which fish are the fastest? Let's take a look!


1. Sailfish

The sailfish stands out as the fastest fish in the world, a title it proudly holds thanks to its remarkable adaptations and evolutionary prowess. In fact, the sailfish can reach top speeds of 68 mph (110 km/h).

Inhabiting the warm waters of the Indian and Pacific oceans, the sailfish features a streamlined shape that epitomizes hydrodynamic efficiency. Its powerful muscles that contract rapidly, propelling it through the water at velocities that top out during short periods of high-speed pursuit.


Fins Fit for Speedy Evasion

What really sets the species apart from other fish are its numerous fins arrayed with precision along its sleek body. The sail-like dorsal fin, from which it derives its name, along with dorsal fins projecting from the back and pectoral fins on the sides, play a crucial role in maneuverability and stability.

Meanwhile, the tail fin and anal fins provide the forward propulsion needed to reach top speeds.

Beneath its sleek exterior, bony spines add to its structural integrity, allowing for bursts of speed that captivate and intrigue marine biologists and enthusiasts alike.

These aquatic speedsters have an alternate use for their sail-like dorsal fin. While it helps them cut through water with minimal resistance, they also sometimes raise it to intimidate predators. Nature loves a multi-tool.


2. Swordfish

Diving deeper into the ocean, the swordfish emerges as another one of the fastest fish out there. The maximum speed of a swordfish is about 60 mph (94 km/h).

Known for its iconic elongated bill, resembling a sword, this species cuts through the water with precision and agility. The swordfish's large, powerful muscles enable quick bursts that propel the fish forward, allowing it to navigate through the water at speeds that leave observers in awe.


Swordfish can withstand particularly cold water temperatures because of a specialized organ located near their brain, known as a countercurrent heat exchange mechanism.

This special organ literally heats their brain and eyes, allowing them to think clearly in colder waters. It also helps them effectively see and hunt their prey.


3. Wahoo

In tropical and subtropical waters around the world, the wahoo is a name that evokes with speed and agility. This striking fish is celebrated for its ability to reach speeds that make it a formidable predator and a sought-after prize among sport fishermen. The maximum speed for a wahoo is about 48 mph (77 km/h).

The wahoo's slender, torpedo-shaped body is perfectly adapted for high-speed pursuits, allowing it to dart through the water with incredible acceleration. Its streamlined form minimizes drag, enabling the wahoo to slice through the ocean currents as it chases down its prey with ruthless efficiency.


One fascinating feature of the wahoo is its series of sharp, serrated teeth, capable of slicing through its catch (typically smaller fish and squid) with ease.

4. Atlantic Bluefin Tuna

Among the giants of the sea, the Atlantic bluefin tuna commands attention not only for its size but also for its ability to swim faster than many of its oceanic counterparts. In fact, it's the fastest tuna in the world, reaching top speeds of 44 mph (70 km/h).

This species combines brute strength with a hydrodynamic silhouette, and its muscular body is supported by a series of finlets on the dorsal and ventral sides, reducing drag and allowing for swift, efficient movement.


An intriguing aspect of the bluefin tuna is that they must keep swimming in order to get enough oxygen from the water. Like some shark species, Atlantic bluefin tuna must keep swimming forward with their mouth opens to keep their blood oxygenated; they don't have the ability while they're stopped.

Additionally, Atlantic bluefin tunas have a countercurrent exchanger that allows them to regulate body temperature in cooler waters. This allows them to hunt efficiently in cold water, much like swordfish.


5. Mako Shark

The mako shark, found in tropical and temperate waters around the world, is the fastest known species of shark, reaching a maximum speed of 46 mph (74 km/h).

The mako's sleek, streamlined body allows it to chase down swift prey, with its powerful caudal fin, shaped like a crescent moon, acting as a propulsive force. The endothermic system of this species also allows it to maintain a body temperature higher than the surrounding water.


Like the bluefin tuna, the mako shark must keep swimming in order to live. It needs water to constantly pass through its gills to create oxygen for in order to breathe. If make sharks stop swimming, they won't survive.

Additionally, mako sharks can remarkably see in the dark. Unlike many other sharks who rely on electroreception to navigate, the mako uses their smell, hearing and vision. These sharks have light-detecting cells and a tapetum lucidum (like cats!) that helps them to see in the dark. This trait combined with their strong sense of touch, allows them to sense tiny pressure changes and movements in the water.


6. Blue Shark

Gliding through the deep waters of temperate and tropical oceans (the Indian, Pacific and Atlantic ocean), this species can reach a maximum speed of 43 mph (69 km/h). Their speed and stamina allow them to traverse vast distances in their quest for food and mating grounds.

These slender, indigo-colored predators are designed for endurance and speed, with long, lithe bodies that cut through the water with minimal resistance.


Their elongated pectoral fins enable them to maintain stability and maneuver with precision, while their powerful tails provide the propulsion necessary for sudden bursts of speed.

Blue sharks' migratory patterns, which are among the longest in the shark world, reflect their search for food and warm waters. Blue sharks have been known to travel across entire ocean basins, a testament to their stamina, adaptability and efficiency.


7. Bonefish

In the shallow, clear waters where the ocean meets the land, the bonefish emerges as a silent sprinter, known for its ability to reach speeds of 40 mph (64 km/h).

The bonefish's torpedo-shaped body and large, powerful tail fin work in unison to propel it forward with bursts of speed, enabling it to escape predators and navigate through its complex, reef-studded habitats with ease.


Bonefish are capable of surviving in shallow, brackish backwaters because they have a special, lung-like air bladder. Essentially, bonefish can suck in air and then hold onto it, allowing them to breathe comfortably in low-oxygen waters.

You'll likely find them moving with the tide, taking advantage of deep water and increased oxygen at low tide and in the shallower flats during high tide where they can hunt for their food.


8. Striped Marlin

Navigating the tropical and temperate regions of the Indo-Pacific Ocean is the striped marlin. Recognized for its striking appearance and formidable speed (with top speeds reaching 50 mph (80 km/h)), the striped marlin is a creature of beauty and power.

Its sleek, streamlined body — equipped with a distinctive bill and pronounced dorsal fin — combines with a flexible spine, allowing it to propel itself forward at high speeds, making it one of the ocean's most efficient predators.


The striped marlin uses its sharp bill to stun prey, a technique that showcases its intelligence and adaptability. While you might think it would impale its victims, it actually stuns them by slashing sideways.

The marlin's speed, combined with this hunting strategy, makes it a master of the marine environment, capable of capturing a wide variety of prey.


9. Black Marlin

Though experts believe the black marlin's swimming speed is around 30 mph (40 km/h), they are capable of reaching much higher speeds in short bursts. The BBC even recorded one reaching 80 mph (128 km/h)!

This impressive species, with its robust, cylindrical body and spear-like upper jaw, is engineered for speed. The black marlin's powerful tail fin, split into two crescents, acts as a propulsive force. Its sleek physique minimizes drag, allowing the black marlin to dash through the water with remarkable efficiency.


This fish has a reputation as one of the most sought-after game fish. Sport anglers from around the world dream of hooking a black marlin, not just for the thrill of the catch but also for the respect earned from battling such a swift and formidable opponent.

10. Fourwing Flying Fish

Soaring above the surface of subtropical waters of the Pacific and Atlantic oceans, the fourwing flying fish represents hits top speeds of 37 mph (60 km/h).

This species has evolved not just to swim but to glide over the water, using its uniquely developed pectoral and pelvic fins as wings.

These "four wings" enable the fish to escape predators by making powerful leaps out of the water, propelling themselves through the air at considerable speeds. The streamlined body of the fourwing flying fish reduces drag both in water and air, reaching impressive heights of nearly 4 feet (2 meters).

It can also glide for very long distances, typically up to 650 feet (200 meters). That said, records have shown that they're able to make consecutive glides of up to 1300 feet (400m).

11. Barracuda

Lurking in the shadows of coral reefs and seagrasses, the barracuda is an intimidating presence in the marine world, known for its sharp snouts and the ability to reach speeds of 36 mph (58 km/h) in short bursts.

With a sleek, streamlined body and a robust tail fin, the barracuda is built for rapid acceleration, allowing it to ambush prey. Its elongated body is perfectly adapted for slicing through the water with minimal resistance, and its large, pointed teeth are ideal for seizing and holding onto slippery fish.

That said, barracudas are curious and often misunderstood nature. Despite their fearsome reputation, they are usually not a threat to humans unless provoked.

We created this article in conjunction with AI technology, then made sure it was fact-checked and edited by a HowStuffWorks editor.

Frequently Asked Questions

How do fish like the sailfish achieve such high speeds?
Fish like the sailfish achieve high speeds due to their streamlined body shape, powerful muscles, and specially adapted fins that reduce drag and increase propulsion.
What adaptations help the swordfish swim in cold water?
Swordfish have a specialized organ near their brain, known as a countercurrent heat exchange mechanism, that heats their brain and eyes, allowing them to function in cold waters.