A tourist on a boat that was struck by lava off Hawaii’s Big Island said he shielded his girlfriend and waited for death as searing debris came ripping through the roof of the boat.

Kilauea, which has been active for decades, began its latest eruption on 3 May 2018 and has destroyed more than 700 homes since.

Will Bryan, a 38-year-old paramedic who was on holiday in Hawaii said: "I remember getting hit with the lava in my back and just waiting for the heat.

"I just assumed that whatever hit me was lava and I was going to burn and die."

His girlfriend, Erin Walsh, 31, was sitting next to him when lava rained down on them earlier this month.

She explained she was so traumatised she could not be around a clothes dryer because the sound reminded her of the harsh sounds of lava that struck the boat.

"It’s getting better each day, but I definitely feel like I’m kind of suffering from some PTSD," she said.

The two were on a 49-passenger sight-seeing boat that takes people to see lava from the Kilauea volcano entering the sea.

  • Footage captured by Will Bryan

Mr Bryan was sitting on the side of the boat closest to the explosion when it happened and captured the event on video.

The footage shows the lava blasting from the ocean and the sounds of rocks and debris pinging off the metal boat as people screamed.

"You can see in my video, there’s like a flash of orange light and that’s when that rock went through the roof," Mr Bryan said. "I just remember worrying, ‘There’s going to be another one that’s going to hit us’."

Graphic locates Kilauea volcano on Hawaii Credit: PA Graphics

"Everybody oohed and aahed," Mr Bryan said.

But that changed as the boat got closer.

"You can hear the oohs and aahs stopping. Everyone started to get nervous," he said.

The vessel made several passes in front of the plume, getting closer each time. Mr Bryan said "mob mentality" prevented him and others from speaking up about their fears of getting too close.

"This stuff was magical and exciting, and no one was saying a word," he said.

Lava from Kilauea volcano's erupting in the Leilani Estates neighbourhood. Credit: AP

The smoke and debris engulfed the boat, Mr Bryan explained, and everything went black.

"There was nowhere to hide on that boat, it’s so small, and it was coming from above us and it was coming from the side of us, there was nowhere to go," he said of people scrambling for safety.

Seconds after the initial blast, the large chunk of molten rock crashed through the roof.

The glow of lava from Hawaii's Kilauea volcano is seen through a plume of gas as it enters the ocean. Credit: AP

Mr Bryan and a doctor stabilised a woman who suffered a fractured leg, the most serious injury of those aboard. The other 22 people injured were treated for minor burns and scrapes, including 12 who were treated at a hospital.