Marconi made the first demonstration of his system for the British government in July 1896.
A further series of demonstrations for the British followed, and, by March 1897, Marconi had transmitted Morse code signals over a distance of about 6 kilometres (3.7 mi) across Salisbury Plain.
On 13 May 1897, Marconi sent the first ever wireless communication over open sea – a message was transmitted over the Bristol Channel from Flat Holm Island to Lavernock Point near Cardiff, a distance of 6 kilometres (3.7 mi).
The message read "Are you ready".
The transmitting equipment was almost immediately relocated to Brean Down Fort on the Somerset coast, stretching the range to 16 kilometres (9.9 mi).

Impressed by these and other demonstrations, Preece introduced Marconi's ongoing work to the general public at two important London lectures: "Telegraphy without Wires", at the Toynbee Hall on 11 December 1896; and "Signalling through Space without Wires", given to the Royal Institution on 4 June 1897.

Numerous additional demonstrations followed, and Marconi began to receive international attention.
In July 1897, he carried out a series of tests at La Spezia, in his home country, for the Italian government.
A test for Lloyds between Ballycastle and Rathlin Island, Northern Ireland, was conducted on 6 July 1898.
A transmission across the English channel was accomplished on 27 March 1899, from Wimereux, France to South Foreland Lighthouse, England.
 Marconi set up an experimental base at the Haven Hotel, Sandbanks, Poole Harbour, Dorset, where he erected a 100-foot high mast.
 He became friends with the van Raaltes, the owners of Brownsea Island in Poole Harbour, and his sailing boat, the Elettra, was often moored on Brownsea or at the Haven Hotel when he was not conducting experiments at sea.

In December 1898, the British lightship service authorized the establishment of wireless communication between the South Foreland lighthouse at Dover and the East Goodwin lightship, twelve miles distant.
On 17 March 1899, the East Goodwin lightship sent the first SOS message, a signal on behalf of the merchant vessel Elbe which had run aground on Goodwin Sands.
The message was received by the radio operator of the South Foreland lighthouse, who summoned the aid of the Ramsgate lifeboat.

In the autumn of 1899, the first demonstrations in the United States took place.
Marconi had sailed to the U.S. at the invitation of the New York Herald newspaper to cover the America's Cup international yacht races off Sandy Hook, New Jersey.
The transmission was done aboard the SS Ponce, a passenger ship of the Porto Rico Line.
Marconi left for England on 8 November 1899 on the American Line's SS Saint Paul, and he and his assistants installed wireless equipment aboard during the voyage.
On 15 November Saint Paul became the first ocean liner to report her imminent return to Great Britain by wireless when Marconi's Royal Needles Hotel radio station contacted her 66 nautical miles off the English coast.
Marconi made the first demonstration of his system for the British government in July 1896. A further series of demonstrations for the British followed, and, by March 1897, Marconi had transmitted Morse code signals over a distance of about 6 kilometres (3.7 mi) across Salisbury Plain. On 13 May 1897, Marconi sent the first ever wireless communication over open sea – a message was transmitted over the Bristol Channel from Flat Holm Island to Lavernock Point near Cardiff, a distance of 6 kilometres (3.7 mi). The message read "Are you ready". The transmitting equipment was almost immediately relocated to Brean Down Fort on the Somerset coast, stretching the range to 16 kilometres (9.9 mi).
Impressed by these and other demonstrations, Preece introduced Marconi's ongoing work to the general public at two important London lectures: "Telegraphy without Wires", at the Toynbee Hall on 11 December 1896; and "Signalling through Space without Wires", given to the Royal Institution on 4 June 1897.
Numerous additional demonstrations followed, and Marconi began to receive international attention. In July 1897, he carried out a series of tests at La Spezia, in his home country, for the Italian government. A test for Lloyds between Ballycastle and Rathlin Island, Northern Ireland, was conducted on 6 July 1898. A transmission across the English channel was accomplished on 27 March 1899, from Wimereux, France to South Foreland Lighthouse, England.  Marconi set up an experimental base at the Haven Hotel, Sandbanks, Poole Harbour, Dorset, where he erected a 100-foot high mast.  He became friends with the van Raaltes, the owners of Brownsea Island in Poole Harbour, and his sailing boat, the Elettra, was often moored on Brownsea or at the Haven Hotel when he was not conducting experiments at sea.
In December 1898, the British lightship service authorized the establishment of wireless communication between the South Foreland lighthouse at Dover and the East Goodwin lightship, twelve miles distant. On 17 March 1899, the East Goodwin lightship sent the first SOS message, a signal on behalf of the merchant vessel Elbe which had run aground on Goodwin Sands. The message was received by the radio operator of the South Foreland lighthouse, who summoned the aid of the Ramsgate lifeboat.
In the autumn of 1899, the first demonstrations in the United States took place. Marconi had sailed to the U.S. at the invitation of the New York Herald newspaper to cover the America's Cup international yacht races off Sandy Hook, New Jersey. The transmission was done aboard the SS Ponce, a passenger ship of the Porto Rico Line. Marconi left for England on 8 November 1899 on the American Line's SS Saint Paul, and he and his assistants installed wireless equipment aboard during the voyage. On 15 November Saint Paul became the first ocean liner to report her imminent return to Great Britain by wireless when Marconi's Royal Needles Hotel radio station contacted her 66 nautical miles off the English coast.
Guglielmo Marconi