Poë was born on September 11, 1849, in Ireland. His father was William Thomas Poe, a barrister. One of his older brothers was the soldier and politician Sir William Hutcheson Poë.[1] Another older brother, George Leslie Poë, became a Royal Navy Captain.[2]
In May 1875, while serving as a lieutenant on HMS Newcastle, Poë jumped overboard to rescue a man who had fallen into the sea. For this he was awarded the bronze medal of the Royal Humane Society; he rescued another man who'd fallen into the sea in October 1876.[1]
He was made Naval Advisor to the Inspector-General of Fortifications in 1889 and Commander of the Training Squadron in 1897.[3]
Promoted to Commodore 2nd Class by 1899 he commanded the Cruiser Squadron until 1900.