so hidden obstacles could be seen. Doodson was enlisted to work out the tidal patterns using his mechanised calculators. His calculations revealed that 5–7 June would provide the best combination of full moon and ideal tidal conditions and D-Day duly took place on 6 June 1944. By 1943, the staff at Liverpool Tidal Institute for tidal analysis had been reduced to Doodson and six young women. They also did "nighttime fire watch on the roof in tin helmets and trench coats and carrying buckets of water in case an incendiary bomb hit the observatory". Personal life and death Doodson was part of a breakaway sect of the Plymouth Brethren and conscientious objector. He married twice. In 1919 he married Margaret, daughter of J. W. Galloway, a tramways engineer of Halifax with whom he had a daughter, who died in 1936, and he had a son, whose mother died shortly after giving birth in 1931. He married again in 1933 Elsie May, daughter of W. A. Carey, who survived him. He died at Birkenhead on 10 January 1968 and was buried at Flaybrick Hill Cemetery. He Further biographical information is available from the National Oceanography Centre, whose Liverpool facility was formerly the Liverpool Observatory and Tidal Institute, part of the UK Natural Environment Research Council, of which Doodson became director. Awards and achievements In May, 1933 he was elected a Fellow of the Royal Society His nomination reads References External links doodson.m Matlab/Octave function of main tidal waves Doodson's arguments and period. 1890 births 1968 deaths British oceanographers Fellows of the Royal Society Alumni of the University of Liverpool People from Salford