Shark! The word invokes a chilling image: A dark dorsal fin slicing through the surface of calm water. A huge open mouth revealing razor sharp teeth.

Drawn by the sounds of the boat engine, almost 40 sharks congregate around our anchoring dive boat. The sight of these sleek, powerful creatures circling the vessel is enough excitement for some passengers — they decide to stay in the boat. But the rest of us exhibit no fear as we race to gear up and jump in.

A Caribbean Reef Shark circles near the surface of the water.

As Smitty the dive master describes shark behavior and what to expect during this dive, about two dozen four-to-six-foot (1.2 to 1.8 m) Caribbean Reef Sharks and one seven-foot (2 m) Bull Shark circle the boat. The animals also know what to expect, and seem impatient for the action to begin.

We are vacationing in the Bahamas, an island country in the Atlantic Ocean. Over two decades ago, Bahamas’ resort owners and dive masters pioneered predictable shark encounters. Our dive spot lies in the open ocean, a 45-minute boat ride from shore. Many marine experts visit these sites to study shark behavior. The dependable return of these imposing creatures to shallow feeding sites provides the opportunity for enthusiasts to observe and study the underwater world and its inhabitants, and learn that sharks and humans can coexist in the sea. Shark dive operators are careful to feed the sharks only small amounts on an infrequent basis, preventing any dependency on the feedings and altering the shark’s natural behavior.

As the divers descend, columns of eager, enthusiastic bubbles rise to the surface from a depth of 40 feet (12 m). Struggling to control racing pulses and shallow, rapid breathing, divers move into position on the white sandy bottom next to a high-profile coral head. The instructions replay loudly: “Control your breathing, stay on the bottom, stay together, don’t reach out and try to touch the sharks.” Not to worry about that last one!

Smitty asks each person if they are okay, using scuba hand signals. Once the group is kneeling in a semi-circle, backs against the coral head, he signals his brother, Captain Delbert, to drop the bait bucket from the stern platform.