At 10:35 A.M., the support ship Vickers Venturer, then in the North Sea, was ordered to return to the nearest port with the submersible Pisces II aboard (which could be removed and flown to Ireland).
Additionally, at midday the Royal Navy ship HMS Hecate steamed to the accident location to offer assistance with special ropes.
The US Navy offered a submersible belonging to the US Salvage Department, called a Controlled Underwater Recovery Vehicle (CURV-III), which was sent from California, and the Canadian Coast Guard ship John Cabot left from Swansea.

On Thursday 30 August the Vickers Voyager arrived in Cork at 8:15 and loaded the submersibles Pisces II and Pisces V, which had been flown in overnight.
The ship left Cork at 10:30.

At 2 A.M. on Friday 31 August the Vickers Voyager had reached the scene and launched Pisces II with a polypropylene rope attached.
However, the lifting rope broke free of the manipulator arm and the submersible had to return to the surface for repairs.
An attempt made by Pisces V failed to find the crashed Pisces III and returned to the surface after it ran out of power.
Relaunching Pisces V had more success and found the crew at 12:44 P.M. However, an attempt to attach a rope failed.
Pisces V now remained with the stricken Pisces III.
An attempt to send Pisces II down again had to be called off when it suffered a leak.

Even the newly arrived CURV-III aboard the John Cabot was unable to launch due to an electrical fault.
Just after midnight Pisces V was ordered to the surface, leaving the men once again alone.
They were now running out of both oxygen and the lithium hydroxide to scrub the carbon dioxide from the deteriorating atmosphere in the submersible.
Both men were cold and wet and suffering from severe headaches.
At 10:35 A.M., the support ship Vickers Venturer, then in the North Sea, was ordered to return to the nearest port with the submersible Pisces II aboard (which could be removed and flown to Ireland). Additionally, at midday the Royal Navy ship HMS Hecate steamed to the accident location to offer assistance with special ropes. The US Navy offered a submersible belonging to the US Salvage Department, called a Controlled Underwater Recovery Vehicle (CURV-III), which was sent from California, and the Canadian Coast Guard ship John Cabot left from Swansea.
On Thursday 30 August the Vickers Voyager arrived in Cork at 8:15 and loaded the submersibles Pisces II and Pisces V, which had been flown in overnight. The ship left Cork at 10:30.
At 2 A.M. on Friday 31 August the Vickers Voyager had reached the scene and launched Pisces II with a polypropylene rope attached. However, the lifting rope broke free of the manipulator arm and the submersible had to return to the surface for repairs. An attempt made by Pisces V failed to find the crashed Pisces III and returned to the surface after it ran out of power. Relaunching Pisces V had more success and found the crew at 12:44 P.M. However, an attempt to attach a rope failed. Pisces V now remained with the stricken Pisces III. An attempt to send Pisces II down again had to be called off when it suffered a leak.
Even the newly arrived CURV-III aboard the John Cabot was unable to launch due to an electrical fault. Just after midnight Pisces V was ordered to the surface, leaving the men once again alone. They were now running out of both oxygen and the lithium hydroxide to scrub the carbon dioxide from the deteriorating atmosphere in the submersible. Both men were cold and wet and suffering from severe headaches.
Rescue of Roger Mallinson and Roger Chapman