Tim Hill worked at Pulp Kitchen in Ainslie with John, who was restaurant manager, and was with him at work on the evening of March 10, 2012, when he had to be taken to hospital.

After fighting melanoma for almost 10 years, John was told the melanoma had spread again. He died six weeks later, aged 25.

Mr Hill remembers his friend as driven, always starting up projects, and ''a big softie on the inside''.

Sunday's gathering was also to raise awareness of the risks of sun exposure, and Mr Hill said his friend's death had taught him the lesson of sunscreen. ''It was drilled into us as kids, but I actively do it now,'' he said.

Friend Andy Davis said John's death had prompted him to get a mole check. ''You always kind of think that kind of stuff doesn't happen to you or your friends,'' he said, remembering a friend who was always at the centre of a social gathering.

John's mother, Lyn Rowe, fears many young Canberrans might not be protecting their skin from ultra-violet radiation. ''Young people in Canberra are dying - you do not have to live near a beach,'' she said.

She was ''perplexed'' by the tardiness of some secondary schools to introduce protective-hat policies and voiced concern about the lack of shade at some skate parks.

''Baseball caps look cool but advanced melanoma is not cool,'' she said. ''It is not a walk in the park - it is a horror show.''

This was the second gathering to remember John, the date chosen to coincide with marches held across the nation by the Melanoma Institute, although not officially connected.

In Canberra, an average 140 melanomas are diagnosed each year, 30 of them in Canberrans aged under 45, the Sun Smart services co-ordinator for the Cancer Council ACT, David Wild, said.

Young Australians had by far the highest incidence in the world, he said, with melanoma the most common cancer in men aged 15 to 44 and women aged 15 to 24. Sun exposure caused about 95 per cent of melanomas in Australia.

Ms Rowe urged people to seek a second opinion if they had doubts about their health.