“Damn it!” Jotun barked. “Damn it to hell!”

The ship faded into the fog and disappeared.

CHUMBE ISLAND, ZANZIBAR, TANZANIA

THE SHARKS DARTED AT THE EDGES OF THEIR VISION, SLEEK GRAY shapes that offered Sam and Remi Fargo only glimpses of knife-edged fins and flicking tails before disappearing into the curtain of swirling sand. As usual, Remi had refused to pass up the photo opportunity, and as usual she’d asked Sam to serve as scale as she focused her highspeed underwater camera past him and at the feeding frenzy. For his part, Sam was less worried about the sharks than he was the precipice at his back-a hundred-fifty-foot drop off the sandbank into the dark deep of the Zanzibar Channel.

Remi pulled her face up from the camera, smiled with her eyes behind the mask, and gave him an OK sign. Sam thankfully finned forward to join her. Together they knelt in the sand and watched the show. It was July off the coast of Tanzania, which meant monsoon season, which in turn meant the warm East African Coastal Current (EACC) was surging from the southeast until it met the southern tip of Zanzibar, where it split into inshore and offshore currents. For sharks this created a “food funnel” in the eighteen-mile gap between Zanzibar and the mainland as prey fish were driven northward. An irresistible moving buffet, Remi called it.

Sam and Remi took care to stay within what they’d dubbed the Safe Zone, that fifty-yard, crystal-clear water strip off Chumbe Island. Past that was the drop into the channel. The demarcation was hard to miss: The current, moving at six knots or more, threw up a roiling curtain of sand as it scraped along the island’s sandbar. This Sam and Remi had dubbed the Good-bye Zone; step into this rip current without a safety line and you were in for a one-way trip up the coast.

Despite the danger-or perhaps because of it-this yearly trip to Zanzibar was one of their favorites. Along with sharks, prey fish, rip currents, and underwater sandstorms that lasted for months, the EACC offered up treasure-albeit usually bits and pieces worth nothing more than their curiosity factor, but this was enough for Sam and Remi. Over the centuries, ships had been plying Africa’s east coast from Mombasa to Dar es Salaam, many of them laden with gold and gems and ivory bound for colonial empire cities. Countless ships had sunk in and around the Zanzibar Channel, the contents of their holds spilled along the bottom, just waiting for the right current to uncover or move them within reach of curious divers such as the Fargos. Over the years they’d recovered gold and silver coins from the Roman Empire to Spain, Chinese ceramics, Sri Lankan jade, silverware . . . From the fascinating to the mundane, they’d uncovered it. So far on this trip, they’d found only one item of note: a diamond-shaped gold coin so barnacle-encrusted they could make out no details.

Sam and Remi watched the sharks feed for a few more minutes and then, by mutual nod, turned and began finning south along the bottom, each stopping occasionally to use a Ping-Pong paddle to waft at the sand, hoping the lump that had caught the eye might be a hidden bit of history.

Chumbe Island, roughly six miles long and two miles wide, is shaped like a woman’s boot, with the shin, ankle, and forefoot facing the channel, and the back of the calf, the stiletto heel, and sole facing Zanzibar proper. Just above the ankle there was a break in the sandbar, an inlet that led to the lagoon created by the stiletto heel.

After fifteen minutes of trolling along the sand, Sam and Remi reached this stiletto break, then turned west until they were ten yards off the beach, then swung north again to resume their search. Now they became more watchful. It was along this stretch of the sandbar that the main channel pushed dangerously close to the beach, a bubble-shaped salient that narrowed their Safe Zone to a mere forty feet. Remi swam inshore and ahead of Sam by a few feet, each of them frequently checking to make sure the other hadn’t drifted toward the precipice.

In the corner of Sam’s right eye he saw a glint, a fleeting flash of gold. He stopped swimming, settled knees first into the sand, then tapped his dive knife on his tank to get Remi’s attention. She stopped swimming, turned, and finned back to him. He pointed toward the spot. She nodded. With Sam in the lead, they swam toward shore until the sandbanks came into view. A wall of sand nearly twelve feet tall, these banks marked a precipice of sorts where the water depth dropped from chest height to twenty feet. They stopped before the bank and looked around.Remi shrugged Where?

Sam shrugged his shoulders and kept scanning up and down the bank. There. Twenty feet to his right he saw it again, a flash of gold. They swam to it and stopped again. Here the Good-bye Zone precipice was closer still, not eight feet behind their backs. Even at this distance they could feel the surge of the current, like a vortex trying to sweep them into the deep.

Jutting from the bank at waist height was what appeared to be six or seven inches of a barrel’s hoop. Though tarnished and fuzzy with barnacles, in a few places the hoop had been sandblasted by the current, exposing shiny metal.

Sam reached out and fanned the area around the hoop. The exposed portion widened to eight inches, then ten inches, before curving back and disappearing into the bank. Sam moved his paddle upward, hoping to uncover some of the barrel’s staves if the wood hadn’t succumbed to rot.

Sam stopped fanning. He looked to Remi and saw her eyes were wide behind her mask. Above the hoop was not rotted wood but a curved metal facade, mottled green with patina. Sam dropped to his knees and wiggled forward until his chest was nearly touching the bank, then craned his neck and waved his paddle beneath the hoop. After thirty seconds of work a cavity appeared. Gently, slowly, Sam slipped his hand into the hollow and probed the interior with splayed fingers.

He withdrew his arm and backed away from the object until he was again beside Remi. She looked at him with expectant eyes. He nodded back. There was no doubt: Their barrel wasn’t a barrel but rather a ship’s bell.“WELL, THAT WAS UNEXPECTED,” Remi said a few minutes later after surfacing.

“I’ll say,” Sam replied after removing his mouthpiece. Until now, the biggest artifact they’d ever found was a sterling silver trencher from a torpedoed World War II Liberty Ship.

She shed her fins and tossed them over the gunwale onto the afterdeck of their rental-a commuter-style twenty-five-foot Andreyale Joubert-Nivelt express cruiser complete with lacquered teak woodwork and retro subway windows-then climbed the ladder, followed by Sam. Once they’d shed the remainder of their gear and tucked it away in the Andreyale’s cabin, Remi fished a pair of water bottles from the ice chest and tossed one to Sam. They sat down on the deck chairs.“How long do you think it’s been down there?” Remi asked.

“Hard to say. Doesn’t take long for patina to set in. We’d have to see the thickness of the growth on the rest of it. The interior felt fairly unblemished.”

“And the clapper?” Remi asked.

“Couldn’t feel it.”

“Looks like we’ve got a decision to make.”

“That we do.”

Not only did the Tanzanian government have some unorthodox laws when it came to maritime salvage, Chumbe Island was officially known as Chumbe Island Coral Park, a good portion of which had been partitioned as a Reef Sanctuary and a Closed Forest Reserve. Before Sam and Remi could do anything, they first had to determine whether the bell officially lay within either of these protected areas. If they passed this hurdle, then they could in good conscience proceed to the next step: determining the bell’s provenance and/or pedigree, a requirement should they want to stake a legal claim before alerting local officials to the bell’s presence. It was a tenuous tightrope on which they tread. If they reached the far side, they may have a significant historical find on their hands, but on either side of the tightrope were laws that could lead to, at best, having the find snatched away, or, at worst, criminal charges. By law they could take any found man-made objects that required “no extraordinary excavation methods.” Trinkets such as Remi’s diamond-shaped coin were fine; a ship’s bell was a wholly different matter.