During World War II, Gaskell advised the Admiralty Mining Establishment of the Royal Navy on anti-mine counter-measures, alongside Robert Boyd, Francis Crick and other recent science graduates.

[5][6] Journalist Anthony Michaelis has described how, despite an air raid on their facility, the great brilliance of this remarkable group of young scientists began to tell and they moved rapidly ahead.

When one day the Germans laid their latest and to them unbeatable mine, combining acoustic and magnetic trigger mechanisms, the team had forestalled them, and were able immediately to hand sweeping instructions to the crews.

[7] Days after Operation Overlord began,Gaskell had the highly gratifying, but by no means un-dangerous, job of walking the beaches of Normandy and verifying his predictions by making actual measurements of the diameters of mine craters.

George Stephen Ritchie, captain of HMS Challenger, recalled: On the way south from Japan to Manus, Dr. Gaskell had said that he wished to carry out one of his seismic experiments in a deep trench in order to find out something of the structure of the sea-floor in such an area.

Gaskell recalled projecting a Western film for the inhabitants, who had never seen horses and laughed at the sight of them,[15] while Ritchie explained that Challenger's arrival harkened back to an earlier scientific expedition to Funafuti, led by William Sollas for the Royal Society in 1896: An old man remembered the coming of the scientists of the Coral Investigation Committee 50 years before, and he led Dr. Gaskell to the site of the deep borehole, the mouth of the hole being still visible but choked with vegetation.