Ports and memorials
Each ship in the Navy was based at one of three main ports: Portsmouth, Chatham and Devonport (a district of Plymouth). Thus there were 'Pompey' ships, 'Chats' ships and 'Guz' ships (the inhabitants of Plymouth were thought to guzzle Devonshire cream and Cornish pasties).
Each individual sailor belonged throughout his career to one of these three 'port divisions'. A sailor who happened to live near one of the three ports would naturally be assigned to that port division.
Each ship was normally manned entirely by men from her own port division. Normally - but not invariably. If necessary, particularly in the stress of war, vacancies in a ship's crew could be filled by men from one of the other two port divisions.
The memorial on which a dead sailor's name is listed is always that of his own port division - which is usually but not necessarily that of his ship.
Denis O'Brien joined the Navy while his family was still living in Ireland. He was assigned to the Chatham port division.
At the start of July 1914 he was on the old battleship HMS London. On 4 July he began a course at HMS Indus, not a ship but the school for engine room artificers at Devonport. On 30 July, although he was a Chats man, he was assigned to a Guz ship HMS Monmouth. He was one of a crew hastily scraped together at Devonport from newly arrived reservists and men who happened by chance to be at a nearby training establishment. On 4 August, the day Britain declared war, Monmouth left Devonport never to return.
After the War the three memorials were built.
The names of most of Denis O'Brien's Monmouth shipmates were on the Plymouth memorial.
His mother could see the Portsmouth memorial whenever she went near the seafront. It contained hundreds of names from the Good Hope, a Pompey ship, also lost at Coronel with no survivors.
But to see her son's name she would have to go to the monument on the hill at Chatham.