Gressly, who signed the MOU on behalf of the United Nations, said the emergency oil transfer from the Safer needs to start in early June and finish by the end of September to avoid turbulent winds and currents that start in October and continue in the last months of the year which increase the risk of the tanker breaking up and for the transfer operation.
"Waiting beyond then could mean delaying the start of the project by several months, leaving the time bomb ticking," he said.
The Houthis control Yemen's western Red Sea ports, including Ras Issa, just 6 kilometers (about 4 miles) from where the Safer is moored, and the U.N. has been negotiating with the rebel group for years to try to get experts on the tanker to examine it.
Gressly said a U.N.-led mission in March to the Ras Issa peninsula near where the Safer tanker is anchored confirmed that it is rapidly decaying and beyond repair, and "is at imminent risk of spilling a massive amount of oil due to leakages or an explosion." As an example, he said, "the inert air that is used to inhibit explosions has long disappeared."
A skeleton crew of about a half dozen remain on the Safer tanker and have done "heroic work over the years to keep this thing from falling apart," but he said but there's a limit of what they can do "with hardly any resources."
The Safer tanker is a Japanese-made vessel built in the 1970s and sold to the Yemeni government in the 1980s to store up to 3 million barrels of export oil pumped from fields in Marib, a province in eastern Yemen that is currently a battlefield. The ship is 360 meters (1,181 feet) long with 34 storage tanks.
Gressly said the U.N. estimated the $80 million cost for the emergency operation which includes the salvage operation, leasing a very large vessel to transfer the 1 million barrels of crude oil, and payments for the crew and maintenance for the Safer for 18 months.
The Netherlands, which has been a major player supporting the U.N.'s efforts, will host a pledging conference in the first half of May, he said.
Gressly said he will lead a mission next week to discuss the plan and seek support in Saudi Arabia, Abu Dhabi, Qatar and Kuwait.
He said raising funds for a replacement for the Safer tanker must also start now.
While a final cost hasn't been set, Gressly said it will probably be "an order of magnitude of let's say $25 million" for a used vessel that's probably no longer appropriate for transporting crude oil but is still suitable for storing oil. He explained that any vessel will have to be modified because it needs a large piece of equipment that's attached to the bow of the ship that attaches it to the oil pipeline.