In 1890 the ship was acquired by the General Post Office (GPO) as part of the nationalisation of the British telegraph network.

Cables are more heavily protected at the shore ends because of the greater risk of damage from other ships such as fishing boats.

This was done from narrow footboards on the sides of the bow of the ship by men prevented from falling into the sea only by a line attached under their arms.

Without telegraph connections, Germany could only directly communicate with locations outside Europe through its high-power radio transmitter at Nauen.

A few hours after war was declared at 11 p.m. on 4 August 1914, Alert was sent out from Dover on a planned mission to drag for, and cut, German cables in the English Channel.

He was the only man on board who knew the purpose of the Alert's secret mission as she set sail, and it was his job to ensure the correct cables were cut.

Alert was not accompanied by a Royal Navy escort (none could be spared), which put her in danger of interception by German warships.

A flotilla of unidentified destroyers was spotted approaching, but Alert continued her work and succeeded in cutting the cable just as they arrived.

This was an attempt by Germany to make a secret alliance with Mexico who stood to gain United States territory as a result.

The British claimed they had intercepted the telegram in Mexico to avoid the embarrassment of admitting they were listening to American diplomatic traffic.

[24] In 1918 she was sold into mercantile service with the Brito-Franco Shipping Company of Newcastle and initially reverted to her previous name of The Lady Carmichael.