Pisces III originally had tail fins, which were removed to improve access and handling when the submersible was purchased by Vickers Oceanics.

They were working on laying transatlantic telephone cable on the seabed, approximately 150 mi (130 nmi; 240 km) southwest of Cork in southern Ireland.

[5][11] For Mallinson, this dive was additionally fatiguing, as he had spent over a day previously repairing a broken manipulator on the submarine.

[5][11] During each dive the pilots had to ensure that after every 40 minutes they turned on a lithium hydroxide fan to remove carbon dioxide from the atmosphere and also add additional oxygen.

The crew heard the sound of water entering the aft compartment as Pisces III became inverted and began to sink back to the seabed.

They also decided to allow the carbon dioxide in the air to build up beyond the normal 40 minutes to conserve oxygen, which resulted in lethargy and drowsiness for both men.

[5][14] 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 survey vessel HMS Hecate steamed to the accident location to offer assistance with special ropes.

The United States Navy offered a submersible belonging to the U.S. 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.

The ship left Cork at 10:30 p.m.[5][16] At 2 a.m. on Friday 31 August the Vickers Voyager reached the scene and launched Pisces II with a polypropylene rope attached.

[5] When the hatch finally opened, both crew members struggled to leave the craft, having been confined inside for a total of 84 hours and 30 minutes.

[22] No Time on Our Side, adapted from Roger Chapman's book for Radio Four by James Follett was first broadcast on 2 June 1976.

[23] In August 2013, it was announced that a film depicting the events of the rescue was in development, possibly starring Jude Law and Ewan McGregor.

[24] In July 2021, Mark Gordon Pictures acquired the rights to adapt Stephen McGinty's book based on the rescue, The Dive, into a film.