The fastest animal in the ocean is the sailfish (Istiophorus platypterus), which reaches speeds of approximately 110 km/h in short bursts — faster than a cheetah on land. However, ocean speed rankings are complicated by methodology: different measurement techniques produce different results, and “top speed” in a short burst is very different from “fastest sustained swimmer.” Here is the most accurate current picture of ocean speed, from the fastest fish to the fastest marine mammals.
The Fastest Ocean Animals — Ranked
1. Sailfish — ~110 km/h
The sailfish holds the speed record for marine animals in most sources. Its streamlined body, rigid bill, and collapsible dorsal sail (retracted during high-speed swimming) minimize drag. Like other billfishes, the sailfish is a regional endotherm — warming its eyes and brain for sharper vision during high-speed chases. Sailfish are found in tropical and subtropical oceans worldwide and hunt schooling fish cooperatively in surface waters.
2. Black Marlin — ~80–105 km/h
The black marlin (Istiompax indica) is arguably the most powerful open-ocean fish. Some estimates place its top speed above the sailfish, though these figures are harder to verify. Black marlins are the largest billfish — females can exceed 700 kg — and their combination of size and speed makes them one of the most formidable predators in the open ocean.
3. Striped Marlin, Shortfin Mako — ~70–74 km/h
The shortfin mako shark (Isurus oxyrinchus) is the fastest shark, reaching approximately 74 km/h in bursts. It shares the same family (Lamnidae) as the great white and has similar adaptations — regional endothermy and a lunate tail. The striped marlin reaches comparable speeds. Bluefin tuna are close behind at around 70 km/h.
4. Wahoo — ~77 km/h
The wahoo (Acanthocybium solandri) is widely cited as one of the fastest fish, reaching ~77 km/h. It is a solitary, open-ocean predator in the mackerel family and one of the most prized sport fish for its speed and fighting ability.
5. Flying Fish — ~56–70 km/h (in water)
Flying fish (Exocoetidae) reach high underwater speeds before launching themselves from the water and gliding on enlarged pectoral fins for distances of up to 400 meters. Their “flight” is sustained gliding, not true powered flight, but the combination of swimming speed and aerial capability makes them unique among marine animals.
6. Orca / Killer Whale — ~55 km/h
The fastest marine mammal is the orca (Orcinus orca), reaching burst speeds of approximately 55 km/h. This is sufficient to pursue great white sharks — which reach around 40–56 km/h — effectively. Common dolphins reach ~55 km/h in bursts as well.
7. Great White Shark — ~40–56 km/h
The great white’s burst speed during breach attacks is approximately 40–56 km/h — fast enough to launch its 1,000+ kg body entirely clear of the water, but slower than several of its prey species in a straight-line sprint. The great white compensates through stealth and ambush rather than outright speed.
8. Leatherback Sea Turtle — ~35 km/h
The leatherback is the fastest sea turtle and one of the fastest reptiles. Its speed and endurance support migrations of up to 16,000 km between feeding and nesting grounds.
How Is Ocean Speed Measured?
Speed measurements for marine animals are notoriously difficult to obtain reliably:
- Early estimates were based on fishing line drag speed — unreliable
- Modern methods include acoustic tagging and tracking, high-speed underwater cameras, and satellite telemetry
- Most cited “top speeds” represent short burst maximums, not sustainable speeds
- Sustained cruising speeds are dramatically lower — a sailfish cruises at 10–20 km/h
Key Speed Comparison
- Sailfish: ~110 km/h
- Black marlin: ~80–105 km/h
- Wahoo: ~77 km/h
- Shortfin mako shark: ~74 km/h
- Bluefin tuna: ~70 km/h
- Orca: ~55 km/h
- Great white shark: ~40–56 km/h
- Leatherback turtle: ~35 km/h
- Bottlenose dolphin: ~35–40 km/h sustained
Frequently Asked Questions
Is the sailfish really faster than the cheetah?
In terms of top speed, yes — the sailfish’s cited maximum of ~110 km/h exceeds the cheetah’s confirmed record of ~98 km/h. However, these are short-burst speeds under different measurement conditions, and direct comparisons are imprecise. In sustained speed over longer distances, the cheetah tires rapidly while large ocean fish maintain efficient cruising speeds for much longer.
What is the fastest shark?
The shortfin mako shark (Isurus oxyrinchus) at approximately 74 km/h. The great white shark — despite its fame — is slower at 40–56 km/h burst speed.
What is the fastest marine mammal?
The orca (killer whale) reaches approximately 55 km/h in bursts — the fastest of any marine mammal. Common dolphins and dall’s porpoises can match or nearly match this speed. Blue whales are much slower despite their enormous size — they cruise at around 5 km/h and can sprint to approximately 30 km/h.