The Lost Expedition

After repatriating a mystic artefact to India (Relic - The Indian Hero #1), Izak Kaurben returns to Croatia to resume his vacation. Waiting to greet him at the airport arrivals hall is Chief Inspector Josip Goran of the General Police Directorate, Croatia.
"I need your help," Goran says, as he unpacks a stash of weapons... "To commit a crime."
Before Kaurben can stop him, Goran puts his plan into action: ambush a prisoner transport van and free a Senegalese gangster.
The Senegalese can help locate an old Russian fishing vessel. Aboard this ship is evidence that Goran seeks — at any cost — to solve a case that is deeply personal to him.
From Croatia to the world's largest ship graveyard in Mauritania, to the Archivo General de Indias — the greatest repository of the Spanish Empire's history in the New World, to the Caribbean Islands, Izak Kaurben is in a race against time and unknown adversaries...
Because the ship has another secret — one that will rewrite history and point the way to a fabled treasure horde.