An avid Brisbane fisherman has fulfilled widower Ray Johnstone's wish for a fishing mate, giving him an all-expenses-paid fishing trip off the Queensland coast.

Mr Johnstone posted an ad on Gumtree on January 19 explaining that his previous fishing mate had died and he was looking for company on his trips.

The ad, which went viral, saw Mr Johnstone being inundated with offers to cast a line from all over the country.

By the end of January, Ray Johnstone's advertisement had already received more than 50,000 views. ( Gumtree: Ray Johnstone )

Mati Batsinilas, 22, from West End was one of the people who answered the call after he saw the post being shared on Facebook.

"When I read it I thought it was a heartbreaking story so I commented on it, but I never thought it would ever get to Ray," he said.

"When I woke in the morning after posting the comment it had 1,600 likes and more than 500 messages in my mailbox on Facebook.

"Everyone was trying to get Ray and I hooked up together to do this trip."

Mr Batsinilas got in touch with Mr Johnstone and offered to take him fishing at Stradbroke Island.

"I offered him a holiday away — and not just for fishing, but to get away and relax," he told ABC Radio Brisbane's Craig Zonca.

"I said from the beginning to Ray that we would get there and that I would commit to it and do it."

Fishing, 4WDing and catching beachworms

The duo were in Moreton Bay on Monday afternoon, seeking out whiting.

"We got about 25 at the moment and we're doing it to get Ray onto some big fish hopefully," Mr Batsinilas said.

Ray Johnstone and his new fishing mate Mati Batsinilas on Stradbroke Island. ( Supplied: Mati Batsinilas )

"The weather gods have been on our side, which is cool."

On Wednesday Mr Batsinilas hoped to take Mr Johnstone four-wheel-driving and to catch beachworms on the beach before he heads back to South Australia.

"He's here now and it's unreal ... I can't explain it in words," Mr Batsinilas said.

"It's so good to see him smile.

"The feedback has been unreal and the support from everyone has been phenomenal."