Born in Newton Abbot, Devon, the son of a bank manager whose ancestors had crossed the River Tamar to Plympton from the Duloe, Morval area of East Cornwall a couple of generations previously. Hambly was educated at Kelly College, Tavistock, Devon. He studied at Newton Abbot School of Art under Wycliffe Egginton and Conway Blatchford, and repeatedly said that Egginton, whom he considered a great watercolourist of Dartmoor subjects, had been the strongest influence on his work.

He went on to Bristol Municipal School of Art where he studied etching under Reginald E J Bush.  He completed his Art Teaching Diploma in 1925. After a brief spell teaching at Weston super Mare and then Salisbury Schools of Art, he moved to Cornwall and became Headmaster of Camborne and Redruth School of Art. He taught art at Redruth Boys and Camborne Girls County Schools along with day and evening classes He was also involved in the work of the Workers' Educational Association. Among his students at Redruth were Marion Grace HOCKEN and Sven BERLIN. Hambly considered Berlin to be the best and most hard-working student he had ever had. Together with his etchings and watercolours Hambly also designed the seal of the local Council, and the East Window above the High Altar in St. Andrew's Church, Redruth showing Carn Brea, Wheal Euny and Redruth Clock Tower.

He exhibited at RI from 1938 until 1966, at Royal West of England Academy from 1926 and at St Ives Society of Artists from 1929 until 1973. He became a member of RWA in 1964 after years as an associate member.

After WWII he suffered a bout of TB which prevented him working temporarily. In 1956 he took early retirement to allow himself more time to devote to his own painting. He left Redruth after a 30 year teaching career and went to live at Downside Vicarage, Chilcompton, Somerset, with Rev Lionel Greenway and his family. They had become great friends in the 1930s while Lionel Greenway was curate at St Andrews Church, opposite the Art School in Clinton Road, Redruth. He died following a heart attack in November 1973 and was buried in Downside Churchyard.