Wadjemup, which means place across the water where spirits live, was a prison island for Aborigines between 1838 and 1903. More than 3700 men and boys were incarcerated in that time.
The island is still home to hundreds of unmarked Aboriginal graves.
Mr Simmons was part of the first all-Aboriginal team to swim to the island in the 2014 Rottnest Channel Swim and he said the minute he set foot on the island, he turned around to leave.
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READ NOW“The swim (to Rottnest) was really heavy for us,” he said.
“It’s a place of mourning for us; it’s like going to Karrakatta for a holiday.
“I never go there.
“When we arrived, I turned around and went straight back (to Perth).”
Documentary filmmaker and Curtin University lecturer Sally Goldrick captured the moment for the documentary Whadjuk to Wadjemup.
“I knew that despite this dark underlying history, this was a positive story that needed to be told and watched by the next generation,” Ms Goldrick said.
Mr Simmons said it was important for him to participate in the swim, which he called significant.
“I hate swimming and I’m not very good (but) it’s a first in history and it shines a light on the shallow, unmarked graves,” he said.
Mr Simmons said he hoped to see the State Government properly acknowledge the island’s past.
“I try to do things, to teach young people to concentrate on the positive,” he said.
The film was nominated for an Australian Teachers of Media Award in the short-form documentary category.
Whadjuk to Wadjemup is available to view online through SBS On Demand and will air throughout the year on indigenous channel NITV.