Following the failure of two French invasion attempts on the Island in 1779 and 1781 the idea of creating an early warning system that could also pass messages to Guernsey was revived. In 1792 work began on building a chain of ten signal stations around the island; these were manned by the Royal Navy because they were used to signalling in code using flags and pennants. At night cannon and fire beacons were used. In 1811 the Lieutenant Governor, General Don, re-iterated his instruction that if the Island was threatened by invasion then a red flag would be hoisted to the top of the mast at Mont de la Ville (Fort Regent), the size and direction of the enemy fleet would be indicated by the number of balls placed on the yards. The alarm would sounded around the island by cannons and the parish church bells would be rung.
While General Don’s book shows that each station had one main mast and two yards, all the historic images of Fort Regent show only one yardarm and this is confirmed by the signal cards included in the various almanac since the early 1840s. Over the years different signals have been made to convey information to the merchants and port authorities and these were printed in the tradealmanacs which were published annually. These generally involved hoisting the house flag of whichever company the approaching vessel belonged to and then a box and pennant to indicate direction. Fort Regent signal station continued to be owned by the War Department until 1958 when the States of Jersey bought the entire Fort (excluding South Hill) for £14,500. In recent years the most frequent commercial harbour activity has been in the hands of the ferry operators and, as they run to a timetable, the hoisting of house flags had limited information value.
In 1861 Admiral Fitzroy introduced the idea of hoisting a black triangle when a gale (Beaufort force 8 and above) was to be expected. This
became known as the storm cone. In 1969 the States of Jersey took over responsibility for gale warnings from the Board of Trade. It was about this time that a ball was hoisted beneath the cone if a wind of force 6 or 7 was expected. Since 2005 the signal station has been operated by a team from the Jersey Heritage boat shop in the Maritime Museum
Today the signal mast is dressed over-all for the usual special occasions, and while it is no longer possible to fly the house flags of vessels in port,
whenever visiting warships enter harbour the relevant national flag is hoisted. The Pilot Jack (a Union Jack with a white border) is hoisted for visiting tall ships and the T flag is flown to mark tides over 38ft (11.6m). Armed Forces Day, Merchant Navy Day and Trafalgar Day are marked by the flying of relevant flags or ensigns and the illuminated Christmas star and Easter Cross are hoisted to mark these religious festivals.