The speakers also included descendants of the Indigenous community who were affected by nuclear testing in Australia in the 1950s, as part of the organisation's ‘Making Waves’ tour. The arrival of the Peace Boat in Sydney, and the group's advocating that follows, aims to inform the public of the severe consequences of the use and testing of nuclear weapons.
Akira Kawasaki, an executive committee member of Peace Boat, told the crowd in Sydney he was sure the Australian and Japanese governments would sign the treaty eventually.
"It’s the end of nuclear weapons, or the end of us," he said. He described the weapons as "inhuman" and "unacceptable on any ground".
Karina Lester, whose father was blinded by the Emu Field nuclear tests of 1953 in South Australia, also travelled aboard the Peace Boat. Ms Lester says his community is still suffering from the impact of nuclear testing today – with skin irritations, eye infections, respiratory problems and autoimmune diseases among the effects.
"Do we want nuclear weapons to be killing us or do we want to get rid of nuclear weapons?" she said.
Peace Boat is a non-governmental and not-for-profit organisation based in Japan, where it has been working to promote peace, sustainable development and human rights since 1983.
Professor Tilman Ruff, a founding member of the International Campaign to Abolish Nuclear Weapons (ICAN) said the treaty recognises the "disproportionate impact of nuclear weapons on Indigenous people" while providing a "categorical, comprehensive prohibition on everything to do with nuclear weapons".
Broken umbrellas were on display during the rally to symbolise the term ‘nuclear umbrella’. The term is often used to describe countries that don’t have nuclear weapons but depend on the nuclear weapons of another country.
"Potentially, we might be willing for nuclear weapons to be used in our name for our protection," Professor Ruff told SBS News.
"If you're threatening to use them you will become a target for other people's nuclear weapons."
Fifty states have signed the Treaty on the Prohibition of Nuclear Weapons.
The Making Waves tour started in Fremantle before making stops in Adelaide, Melbourne, Hobart, and now Sydney.