It was Suresh, the sonar expert. Tusker had met him back in Galle when they were surveying the harbor. Tusker remembered giving him a hard time for being afraid of the water, threatening to push him overboard if he didn’t behave. His body was pressed up against the inside of the cabin window, pinned by the buoyancy of his orange life jacket, which he always dutifully donned before leaving the dock. Tusker looked at Ian and could tell he’d seen the same thing.

Tusker settled on the sand bottom where the Taprobane rested and checked his depth gauge. 187 feet. He briefly watched the march of the Aquastar’s seconds hand tick tick tick around the dial. Its steady precision calmed him. Ian nudged him with a quizzical look. Snap out of it, man. At this depth, the nitrogen in the air they were breathing had a narcotic effect. It affected people differently. Some got paranoid, others panicked, but for Tusker, it caused time to slow down. On some deep dives he’d become obsessed in minutiae, staring at the nibbling of a fish or the seconds hand of his watch in what afterwards felt like a timeless fugue state.

A newly sunken 46-foot wreck is easier to explore than a larger, older one. While Tusker explored the torn rear dive deck and cabin, Ian swam down the length of its white hull and around behind the transom, which had been customized by MOCHA to allow easier entry for divers climbing the ladder. Then he saw the gaping wound in the boat’s port-side hull. The white aluminum was now black and twisted. He could see into the engine compartment through the ragged gash. He banged his tank to get Tusker’s attention.

Tusker swam down to Ian and saw the maw in the hull. He reached into the pocket on his harness belt and took out a measuring tape. He ran it along the hole in the hull and made note of it on a waterproof slate strapped to his wrist. He pulled the knife from its sheath on his lower leg and prised off a small flapping piece of the torn steel hull. He swam a few feet away to take another look. Tusker thought for a moment. This wasn’t the result of any scuba tank exploding. The pattern of damage reminded him of sunken warships he’d surveyed that had been hit by torpedoes or collided with mines.

Ian was below, scouring the sea floor for clues. It occurred to Tusker that Ian was spending longer at greater depth than he was. He can take care of himself.