A fog alarm consists of a diaphone, which during thick or foggy weather, will give blasts of five secondsí duration every two minutes, thus: blast of 5 seconds, silent 115 seconds, blast of 5 seconds, silent 115 seconds.In 1907, mariners were notified that on April 1 of that year, the fog alarm on Cainís Island would be changed to sound six-second blasts separated alternately by silent intervals of fifteen and ninety-three seconds, thus: blast six seconds, silence fifteen seconds, blast six seconds, silence ninety-three seconds. Starting in June of that year, a red lens-lantern light was exhibited from the roof of the engine house to guide vessels entering the harbour of Rose Blanche. In 1912, a covered passageway was built to link the dwelling to the engine house.
The engine house is a square, flat-roofed building, painted in alternate black and white horizontal bands.
The keeperís dwelling is a square, flat-roofed wooden building, painted white, roof black.
The storehouse is a square, flat-roofed building, painted white, roof black.
John Garcin was hired as the first keeper of the station and served through at least 1921. The 1921 census shows that John Garcin was sixty-three at that time, and his thirty-two-year-old son John Garcin, Jr. was serving as the assistant keeper. In 1935 and through at least 1945, Llewelyn Gillan was in charge of the station on Cainís Island and James Skinner was serving as his assistant.
In 1990, a combined fog alarm building and lighthouse were removed from Cainís Island, and a large, square, skeletal tower was placed on the island. It appears that this tower served until 2003, when a mast light was placed on the island. In 2021, the mast light was exhibiting a flashing red light with a period of six seconds.
Keepers: John Garcin (1904 Ė at least 1921), Llewelyn Gillam (at least 1935 Ė at least 1945).