What Divers Should Know About Sailfish

Easily identified by its distinctively large dorsal fin, or 'sail', that often stretches along its entire back, the Sailfish (Istiophorus platypterus) is a captivating marine species. Predominantly blue to gray, these impressive fish also feature a prominent elongated rostrum, a characteristic shared with other billfish. Renowned for their incredible speed, recent research indicates they can achieve burst speeds up to 10 m/s (35 km/h). Sailfish grow quickly, typically reaching 1.2–1.5 meters (4–5 ft) in just a single year.

An epipelagic and oceanic species, Sailfish show a strong tendency to approach continental coasts, islands, and reefs in tropical and temperate waters of the Pacific and Indian oceans. They feed on the surface or at middle depths, with some populations critically reliant on coral reefs for feeding and breeding. These magnificent fish generally do not exceed 3 meters (10 ft) in length and rarely weigh over 90 kilograms (200 pounds). Interestingly, they are capable of changing colors to confuse prey, display emotion, or communicate with others. While generally not aggressive, documented accounts show they will attack in self-defense if threatened.