Prokoshev told the BBC this was to pick up additional cargo - a consignment of road-building equipment, including heavy rollers.
But someone hadn’t done their calculations. When the cargo was winched on to the ship’s deck hatches, they started to buckle.
“The hatches were rusty, old,” Prokoshev said. “So we couldn’t take it. I refused. It would break the boat.”
The effort was abandoned. Now, with the new crew starting to fear that they might suffer the same fate as their predecessors, Prokoshev says he decided to head for Cyprus to sort things out with Grechushkin.
But before the Rhosus could leave Beirut, the Lebanese authorities intervened.
According to the Lloyd’s List intelligence database, the ship was eventually seized on 4 February 2014, due to unpaid bills totalling $100,000.
Some crew members were allowed to leave, but Prokoshev was ordered to stay, along with his chief engineer, third engineer and bosun, all Ukrainian.
They weren’t even allowed to leave the ship.
“They kept us as hostages,” he told the BBC.
Prokoshev says he tried to enlist the help of Russian President Vladimir Putin, writing to him every month. In a separate interview with Radio Liberty, he says he got a frosty answer from the Russian consulate in Beirut.
“They told me ‘What do you want Putin to do? Send special forces to release you by force?’”
The plight of the crew came to the attention of the International Federation of Transport Workers. In late March, an ITF inspector, Olga Ananyina, said the crew had no means of subsistence.
“The team is on the brink of survival,” she wrote on 28 March 2014.
She said Igor Grechushkin’s company had no money to pay debts, either to the crew or the port, and she sounded a warning.
“In addition to the above problems,” she wrote, “the crew is alarmed by the fact that in the holds of the Rhosus vessel there is a particularly dangerous cargo - ammonium nitrate. The port authorities of Beirut do not allow the unloading or reloading of cargo to another vessel. This fact further complicates the already difficult situation of seafarers.”
Hers wasn’t the only warning. Four months later, an article on the trade website FleetMon highlighted the same danger.
“Crew kept hostages on a floating bomb,” was the headline on an article posted 23 July 2014.
The article summed up the dilemma.
“The port authorities don’t want to be left with an abandoned vessel on their hands,” it said, “loaded with dangerous cargo.”
The ageing Rhosus was not in good shape, taking on water that had to be bailed out every day. Prokoshev said they were concerned about the cargo.
“We needed to be sure… the cargo was kept dry and not spoiled,” he told the BBC.
“If you live on a boat, you look after it. You don’t want it to sink.”
The crew sold some of the ship’s fuel to pay for legal help. After a three-month court process, Lebanese lawyers finally managed to secure their freedom.
“We closed all the compartments, locked them and handed the keys to immigration at the port,” Prokoshev says.
According to the International Transport Workers’ Federation, Prokoshev and his Ukrainian colleagues finally left Beirut in September 2014.
Grechushkin did apparently pay for their passage to Odessa, but Prokoshev says he’s still owed $60,000 in unpaid wages.
Some time later - it’s not clear when - the ship’s dangerous cargo was also removed.
Abandoned by its owner and its crew, and taking on water, Prokoshev says the Rhosus eventually sank.
According to one analysis - the Rhosus currently sits under water in Beirut harbour, less than a third of a mile from the site of the explosion. According to Lloyds List Intelligence records, the ship "sank in the breakwater in February 2018".