In 1915 he joined the Inns of Court Officer Training Corps and by February 1916 he had been awarded a Commission with the 3rd Battalion of the Welsh Regiment. He kept in touch with his old school, regularly writing letters to the headmaster Dr. Tovey. In the 1918 edition of the Grammar School magazine it was reported: "Godwin Pratt has recently been wounded in France, in the right hand and back; we are happy to be able to say the wounds are not serious. We hear he has applied for a transfer to the R.F.C."
He was transferred to the Royal Air Force on 5th April 1918 and served with the 62nd & 63rd Wings.It is not known in which theatre of war he served before the armistice but the June 1919 edition of the school magazine notes: "When we last heard of Godwin Pratt he was at Petrovsky, 150 miles N. of Baku." He was Mentioned in Despatches on two occasions and was awarded the Victory and British War medals. Following his discharge on 19th September 1919 he rejoined his old engineering firm at Newport. The November 1919 edition of the school magazine shows that he "has been spending a few days at the School. We offer him our heartiest congratulations on being "Mentioned in Despatches" for good work done in South Russia. He has been with a sea-plane squadron on the Caspian Sea."
By the time of the 1939 Register he was living at 1 Wolferton Road, Bristol, Gloucestershire, described as a Commercial Traveller but also serving with the No. 11 Balloon Barrage (929 Squadron) as an Aircraftsman Class 2 (Service No. 861233). His death was recorded in Brighton, Sussex, in 1970.
A "First List of Old Shastonians Serving in H.M. Forces" was produced by Shaftesbury Grammar School in September 1915. It shows the regiment in which Godwin served and the date and term in which he left school. Throughout the was a hand-written list was also compiled of Shaftesbury Grammar School old boys serving in the armed forces. The board is now at Gold Hill Museum.
First List of Old Shastonians Serving in H.M. Forces
Shaftesbury Grammar School Magazine, October 1914
Shaftesbury Grammar School Magazine, October 1915
Shaftesbury Grammar School Magazine, February 1916
Shaftesbury Grammar School Magazine, March 1918
Shaftesbury Grammar School Magazine, June 1919
Shaftesbury Grammar School Magazine, November 1919
Shaftesbury Grammar School Magazine, June 1920