Salvors stand ready to help the United Nations deal with a potentially devastating oil spill from a deteriorating vessel off Yemen.

So far no international inspectors have been allowed on board the floating storage and offloading unit Safer (built 1976), which is carrying 1.14m barrels of crude.

But what are the best options for tackling the rotting ship if clearance is given by rebel Houthi authorities?

Simon Agass, business development manager at risk modeller RiskAware, said the best case scenario is that salvage teams are allowed to pump off the oil and tow away the ship.