Odyssey Marine Exploration's treasure hunting vessel Ocean Alert was boarded by Guardia Civil officers yesterday morning and taken to the port of Algeciras under threat of arrest. The British and Gibraltar governments, together with the company, said the boarding took place in international waters and appeared to be illegal. Spain said it took place in Spanish waters under their jurisdiction.
Once in Algeciras the vessel was searched under an order from a La Linea court and the documents and possessions of those on board were seized for inspection.
The Panama-registered vessel left Gibraltar early yesterday morning having informed the Spanish authorities of its intended departure a day earlier.
The crew on the ship expected to be stopped and boarded, but they were not anticipating being taken into a Spanish port.
The Ocean Alert sailed from the Naval Base at 08.50 and was shadowed out of Gibraltar waters by a Guardia Civil patrol boat.
Three and half miles off Europa Point, the vessel was contacted by the Guardia Civil.
"You are in Spanish territorial waters," a Guardia Civil officer said over the radio. "We are going to board your vessel."
Sterling Vorus, master of the Ocean Alert, replied that his ship was in international waters.
The exchange went on for a few minutes with neither side shifting. The mood on the bridge of the Ocean Alert became increasingly tense.
Finally, with no other choice, Captain Vorus agreed to the boarding and spoke over the radio: "We are in international waters and you are boarding us without our consent."
At around 10am and with the Rock in the distant background, a Guardia Civil patrol boat came alongside the Odyssey vessel and four officers jumped on board, heading straight to the bridge.
The boarding was closely monitored by a Spanish navy corvette and a Guardia Civil rigid-hull inflatable boat, which held position just a few hundred metres away.
The Guardia Civil officer in charge told Captain Vorus that he had an order from the Number Three court in La Linea requiring him to take the Ocean Alert into the port of Algeciras for an inspection by court officers.
The captain was advised that failure to comply would lead to his arrest.
Odyssey lawyer Marie Rogers, who was on board, said: "The master was not given an option. They came on board and that was it."
Odyssey maintains that the boarding was illegal because as far as the company is concerned, it happened in international waters.
The company said that under international law the Guardia Civil officers could only on board if invited by the vessel or its flag state, adding that Odyssey would have willingly allowed them on the ship under those terms.
As late as yesterday evening diplomatic efforts had been underway to arrange just such an arrangement, known as a compliant boarding.
But the Guardia Civil's insistence that the ship was in Spanish waters turned that expectation on its head.
Aladar Nesser, who is in charge of Odysseys International Business Development and was on board the vessel, said: "We made it clear to them that we were being illegally boarded in international waters under threat of force."
Alongside in Algeciras, everyone on board the ship was asked to file off and was frisked as they stepped off the gangplank, though no one was arrested.
No one was exempt from the checks. Your correspondent had his laptop, camera and notebook confiscated. The Odyssey lawyer also had a work laptop filled with confidential client information confiscated.
All that material was sealed in evidence bags by judicial officers from the Guardia Civil and was still in their custody as this edition went to press.
Last night the ship remained alongside in Algeciras under guard by the Guardia Civil and all access was restricted.
The court order from La Linea includes allegations that Odyssey may have broken Spanish heritage laws. The claims cover a period dating back to 2001.
As this edition went to press, lawyers for the company were assessing the situation and preparing a course of action for the coming days.
The governments of the UK, the US and Gibraltar were also closely monitoring developments. Representatives of the Panamanian government had also been contacted.
Yesterday's developments represent a marked escalation in a controversy that has raged for weeks since the company announced it had recovered a valuable treasure from an unidentified wreck - codenamed Black Swan - in the Atlantic.
Odyssey says the Black Swan was discovered in international waters but Spain is convinced it may have a right to a claim. There is also a suspicion in Madrid that the treasure trove may have been illegally recovered in Spanish waters, a claim Odyssey rejects.
Since the find was announced, Odyssey, along with British and US diplomats, has tried to reach a negotiated solution to the impasse, which has kept its two ships - Ocean Alert and Odyssey Explorer - effectively blockaded in Gibraltar.
The company thought it had reached a breakthrough this week but having tested its position in practice yesterday, the outlook now looks more complicated than ever.
As the incident unfolded at sea yesterday morning, a British Government spokesman in Gibraltar confirmed that the matter was being formally raised with the Spanish Foreign Ministry in Madrid.
He said the British position is that the waters in which Ocean Alert was detained are international, not Spanish.
While the detention of the vessel was a matter for the Spanish Government and the flag state of the vessel - Panama - the UK nevertheless did not consider that Spain had jurisdiction over those waters, and that therefore there was no right to intercept the vessel or crew without the permission of the flag state.
In Gibraltar the Government also issued a statement on the incident.
It stated that the intervention by Spain of a Panamanian ship in international waters was a matter for the Panamanian Government.
"However the Gibraltar Government is concerned that international shipping using Gibraltar port should be interfered with in this way in international waters," the statement said.
"The Gibraltar Government understands that under international law a vessel can only be arrested in international waters with the agreement of the vessel's flag state."
"Assuming that the Panamanian authorities have not given their consent to the arrest of the Ocean Alert, her arrest by Spanish Authorities would appear to be an illegal act."
Issues surrounding the recovery of the treasure are set to be considered in a fortnight by a Miami court, which originally authorised the salvage after Odyssey secured an arrest over the site of the wreck.
The Black Swan treasure includes over 500,000 silver coins weighing more than 17 tons, hundreds of gold coins, worked gold, and other artefacts.
It is believed that this recovery constitutes the largest collection of coins ever excavated from a historical shipwreck site.