THERE was a bright red flag flying over the City Chambers in Glasgow on Saturday. And it was one that provokes deep emotions in thousands of the city's citizens. It was the Red Ensign, the red flag that sports a Union flag in the top left-hand corner, and flown by British ships in every port in the world.

Nowadays the River Clyde in Glasgow is virtually bereft of shipping, but until the sixties it was a thriving port, with many shipping companies based in the city. Going to sea was a passport out of Glasgow for thousands of young men, but during the two world wars it also meant an early death for many as German U-boats pounded the boats bringing vital supplies to Britain.

The civilian sailors in the Merchant Navy - the term given to the mercantile fleet by King George V after World War One - suffered a higher ratio of casualties than any arm of the Armed Forces. Some 15,000 men killed in the first war and over 32,000 in the second. For many of course there was no grave other than being lost at sea, and no grave for their families to grieve at, which is why the Red Ensign being flown at the weekend meant so much to the city's older citizens recalling family and friends who perished at sea.

The occasion was Merchant Navy Day, on the anniversary of the declaration of war in 1939, but more importantly the anniversary of the sinking of the SS Athenia, built in Glasgow and torpedoed by the Germans with the loss of 128 crew and passengers.

Lord Provost Sadie Docherty laid a wreath at the Cenotaph, and spoke for many when she said: "It's with a great sense of pride and shared sorrow that I join with seafaring veterans and their families, to express my gratitude, and the gratitude of the people of Glasgow, for those brave men and women lost at sea defending our shores."

Behind her was a fellow councillor, Bailie Nina Baker, who was a prime mover in having the day recorded at the Cenotaph. Sometimes we don't really know our councillors. Nina, a Green Party councillor, was Britain's first ever female deck officer. And she became the first because of the Suez Crisis. In the early seventies the Egyptian Government had closed the Suez Canal, and suddenly shipping had to go the more circuitous route round Africa and the Cape of Good Hope. More crew members were urgently needed for the longer journeys, and new equality legislation allowed women to gain the necessary qualifications. Nina was the first to apply.

After a career at sea, Nina ended up in Glasgow, was elected to the council, and noted just in the doorway of the City Chambers a plaque to the Merchant Navy which not many folk seemed to know about, which is why she pressed for the Merchant Navy Day each year on September 3 to become more prominent.

Carrying the Merchant Navy Standard at George Square was John Mortimer, who later became a civil servant, but in the seventies was in the Merchant Navy. How was it, I ask. "It was absolutely pure dead brilliant," says John, and he rhymes off his varied and colourful career, including transporting the first 17 giraffes and 6 wildebeest from Dar es Salaam in Africa to Blair Drummond Safari Park.

But it was the plight of the sailors in the wars that he wanted to remind people about. "Do you know that Merchant Navy seamen were paid off the day that their boat was sunk? They even had to buy their own clothes after they were rescued. There were sailors on the Russian convoys, wounded, who couldn't get home from Russia as their shipping lines turned their backs on them. The British consul was so embarrassed he paid for 17 men for their journeys home himself."

He simply adds: "We could not have won the war without the Merchant Navy."

But the ceremony was not just about looking back. Attending George Square were cadets from the nautical studies faculty of Glasgow City College. Two of them read out names of the dead from the Merchant Navy Roll of Honour kept at the City Chambers. One of the cadets was Hannah Beebe from Greenock who is training to be a deck officer, and has already been to sea as part of her training.

She had gone to university, decided it wasn't for her, and switched to the nautical college where she is one of only a handful of female students, but says she has encountered little or no prejudice because of her sex. "People have been very helpful, including the crews at sea," she says. But what about the physically challenging bits of the job? Says Hannah: "Anything I can't lift by myself I get help. And it's things that males shouldn't be lifting by themselves anyway."

She wants to travel, wants to work on gas tankers, and possibly cruise ships. I ask if her mother worries about her travelling the world in ships, but she has sensibly worked out that her mother, like all mothers, worries when she steps out the door every morning, so being aboard or not being aboard a tanker, would not make much difference.

Dr Nicola Crawford, faculty director at the college, said it was important to remember the sacrifices that have been made in the past. "Events like this serve to remind everyone that the Merchant Navy is more than just a job – it’s an essential part of life."

There may not be wars for the British Merchant Navy to endure just now, but the separation from families and the heavy work can lead to depression, illness and homelessness which is why the charity Seafarers UK uses Merchant Navy Day to highlight the difficulties sailors can face.

But for people like Nina and John, they have nothing but good memories of their time at sea and would recommend it as a career. New recruits like Hannah will ensue that the Red Ensign will be seen in ports around the world for years to come.