Horse-Eye Jack in Cozumel

A deep silver body with a very large eye, a yellow tail, and a steep forehead. Travels in tight schools that hang in the blue and turn as one.

Quick ID

Where You Will See It In Cozumel

Horse-Eye Jack is tagged on reef profiles right along the west coast, across a depth band of roughly 16 to 131 feet.

Without a boat. It turns up at Chankanaab Shallow — a shore entry, so you can dive it on your own schedule.

On an ordinary beginner boat dive. It is recorded at Columbia Shallows and Palancar Gardens. No advanced certification needed.

Deeper, and on the walls. It also shows up on Palancar Caves, Palancar Horseshoe, Punta Sur and San Juan.

Conditions change the odds more than the site does — the current, the time of day and how much the group has already stirred up the sand. Ask your guide what they have been seeing that week.

Behaviour

Schooling predators that use the current line. Schools compress and flash when they turn, which is the moment most divers notice them.

Commonly Confused With

• Bar jack — Bar jack has a black-and-blue stripe running along the back and into the lower tail lobe, and is usually solitary or in pairs.
• Crevalle jack — Crevalle has a blunter head and a black spot on the pectoral fin.

Diving Etiquette And Safety

Nothing required. Look away from the reef during a drift — most divers miss them by staring at coral.

Part of the Cozumel marine life guide · see Cozumel dive sites · plan your Cozumel dive trip

Photo: Andy Blackledge, CC BY 2.0, via Wikimedia Commons.