Rex was born at Eltham, Taranaki, New Zealand on 26 October 1910. He was the son of James Beatson and of Violet Beatson (nee Bailey), of Napier, Hawke's Bay, New Zealand. He was the youngest of four children. His siblings were Stanley Clive Beatson (born 1900), Clara May Beatson (born 1902), and Rita Gladys Beatson (born 1904).

Rex lost his mother before he was 3 years old and was brought up by Mrs Elizabeth Bradford. His sister May passed away when he was 9 years old. His early primary schooling was at Auroa School, Taranaki before going to Tawhiti School in Hawera. He attended Hawera Technical High School from 1924 - 1926. In 1933 while Rex was still living in Hawera he gained his Private Pilot's License - he flew Gipsy Moths. In the same year his father who was living in Napier remarried. Rex worked as a radio mechanic for Collier and Beale Ltd in Whanganui and later in Wellington. He never married.

Rex enlisted in November 1940 and sailed from Auckland in January 1941 on the Empress of Russia for training in Canada.On the 23rd January 1941 with a rank of LAC he was posted to No. 4 Air Observers' School, London, Ontario where he carried out air exercises as navigator on Anson aircraft.The following April he was posted to No. 4 Bombing and Gunnery School, Fingal, Ontario, where he trained Fairey Battle aircraft. On gaining his Air Observer's Badge in May 1941 he was promoted to Sergeant. One month later he was commissioned as a Pilot Officer. By August of that year he was in the Unted Kingdom where he was posted to various Operational Training Units, until in January 1942 he was posted to No. 44 Squadron, Waddington, Lincolnshire. He took part in eight operational flights over enemy territory. These were in Cologne, Stuttgart (2), Essen, Hamburg, and Warnemunde in Germany, and Lorient, the Nazi U-boat base in France. He also took part in one minelaying operation in the Gironde Estuary.

Investigation Report: "On 9th May 1942 Lancaster MK I R 5555 whilst carrying out an attack on WARNEMUNDE was shot down by Flak and crashed at 0200 hrs at LAMBRECHTSHAGEN. On the impact the aircraft caught fire and was burnt out. One of the crew evidently tried to bale out and was injured on coming down. He was taken to hospital at WARNEMUNDE by Flak personnel, where he succumbed to his injuries. The rest of the crew crashed with the aircraft and were killed."

He is buried in the Heerstrasse British War Cemetery in Berlin, Germany.

Attended Hawera Technical High School (Source: RNZAF Biographies (R17845607)) AWMM