He was a strong advocate of the groupflashing system as a means of differentiating lights, and invented an arrangement for carrying it into effect optically, his plan being first adopted for the catoptric light of the Royal Sovereign lightship, in the English Channel off Beachy Head.
Extremity of Nantucket Island is Siasconset (locally 'Sconset), a summer resort of some vogue; it has a Marconi wireless telegraph station, connecting with incoming steamers, the Nantucket shoals lightship and the mainland.
The average depth in the harbour at high water is about 46 ft., with a fall of tide of about 8 ft., the entrance being marked by a lightship and two buoys.
There is a lightship in the Shatt al 'Arab bar, which is very completely buoyed and lighted throughout its length from the lightship to Fao, where there is a fixed light.
In December 1898 communication was established by the Marconi method between the East Goodwin lightship and the South Foreland lighthouse; and this installation was maintained for upwards of a year, during which it was the means of saving both life and property.
With this apparatus some of Marconi's earliest successes, such as telegraphing across the English Channel, were achieved, and telegraphic communication at the rate of fifteen words or so a minute established between the East Goodwin lightship and the South Foreland lighthouse, also between the Isle of Wight and the Lizard in Cornwall.