The first two vessels in a so-called toxic "ghost fleet" of former US Navy ships set sail for Britain on Monday night after weeks of protests by environmentalists.
The ships are currently in the James River in Virginia
A last-minute court bid to prevent all 13 chemical-contaminated ships leaving dock in Virginia, bound for Teesside, failed last week.
The two vessels, the auxiliary oil tankers Canisteo and the Caloosahatchee, were due to leave at 2200 BST on Monday on the three week journey to the north-east of England.
Six tugs will be needed to accompanied the ships to the Atlantic Ocean. From there, one large ocean-going tug will tow them to the Able UK yard in Hartlepool, where they will be scrapped.
Two more of the obsolete ships are free to leave at any time.
Another nine are being held in port while a court battle between the US Maritime Administration and American environmental groups goes on in Washington DC.
The vessels are between 40 and 50-years-old and contaminated with chemicals including PCBs, asbestos and heavy diesel.
Campaigners claim that the ships could break-up during the journey, causing an environmental catastrophe.
THE GHOST FLEET
USS Santa Cruz
USS Santa Isabel
USS Compass Island
Friends of the Earth said it would seek a judicial review in the High Court in London into the decision by the Environment Agency to extend Able UK's waste management licence, to facilitate all 13 ships.
The group's director, Tony Juniper, said: "Unless the Environment Agency revokes or justifies its decision, we will seek judicial review.
"We are extremely disappointed with UK authorities, including the Environment Agency, English Nature and the Coastguard, for agreeing to allow these boats to
come to Teesside.
"Their ghost fleet decision may come back to haunt them.
"These toxic ships should be disposed of in the US, and not sent on a hazardous cross-Atlantic voyage to be dumped on the North East."
Despite the objections Able UK has stated that the vessels, which have been at anchor in James River, Virginia, are safe to make the journey. The claim was
supported by US authorities and the Environment Agency.
The contract is worth £16m to the company and will create about 200 jobs.
Able UK has accused environmental groups of "scaremongering".
US environmental group the Basel Action Network (BAN), said the first two ships contain more than 68 tonnes of toxic PCBs as well as over 120 tons of asbestos.
The network joined the Sierra Club in applying for the emergency restraining order against the ships' departure at the Federal District Court for the district of Columbia in Washington last week.
The application was upheld in part, meaning four ships could sail immediately, but nine more could only depart if approved by a the court following a hearing on 20 October.