Hellenic Coast Guard was established in 1919, when the older Harbour Corps merged with the Anti-smuggling Command of Hellenic Navy. All vessels of latter were transferred to Hellenic Coast Guard, while new vessels entered also service. These were the HCG 01 Class and the HCG 10 Class, each group of 10 vessels. Both were ex British Hunt Class Minesweepers of WW1, of Belvoir and Aberdare Group respectively, bought in barely scrap price in 1919-1920. Modifications were new oil fired boilers, armament was one 6-pdr Hotchkiss and a QF 1-pounder pom pom gun. In 1939-1940 latter was replaced with a single 20mm/L65 Y1935 Naval Mount (lisenced built German 20mm Flak 30 modified with domestic designed drum magazines of 60, 75 rounds). All vessels remaining from WW2 were decommissioned until 1950.
https://en.m.wikipedia.org/wiki/Hunt-cl ... per_(1916)
And links for guns mentioned: