Mark is all set to make waves in his mankini

A Mount Maunganui man is completing this weekend's triathlon wearing only a Borat-style mankini to raise money for his terminally ill mother-in-law.

Mark Stride, 28, said the outrageous tight, green and revealing costume was not the most comfortable thing to wear while swimming, cycling or running but he decided to don it to raise funds for cancer research.

Half the money raised will go towards a plane ticket for his fiancee to travel to Japan to visit her terminally ill mother.

"My fiancee's parents were supposed to come over here for Christmas and New Year but just over a week ago we got the awful phone call saying her mum was diagnosed with terminal cancer at stage 4, so it's not looking too good and they don't know how much longer she's got," he told the Bay of Plenty Times.

"We're saving for our wedding and a house, so I thought I could do this to raise a bit of funds to help get my partner over to Japan. Half of what is raised will go towards cancer research or Cancer New Zealand. I'm not exactly sure which organisation yet though."

His fundraising efforts began at his workplace, Baywave, where colleagues donated a couple of hundred dollars after a staff paintball event.

On Sunday, race day, Mr Stride will be at the Shore Break tent with a collection bucket, if members of the public wish to donate.

His mankini is a $10 outfit from The Warehouse. It doesn't fit him properly - it's too big in some places and too small in others - so he is trying to get a better suit imported from overseas ahead of this weekend's race.

Having thousands of people watch him as he completes the 1500m swim, 40km cycle and 10km run circuit in a mankini was daunting, Mr Stride said.

"Emotionally it will be painful but nowhere near as painful as what [my mother-in-law] is going through. This is nothing in relation to that so, if she can do it, I can endure a bit of pain."

He does not want to get hypothermia, so he might wear a wetsuit during the swim "but that depends on how cold it is on the day". He is also set to wear pantyhose underneath the mankini, as it would help keep everything in place while achieving the bare skin look.

"I don't want this to have any sexual orientation. There are going to be kids there, so I want to keep it clean. With the pantyhose you'll still see skin but it will be a bit safer for me."

Mr Stride is a member of Triathlon Tauranga and Team Shore Break and has been a serious triathlete for about five years. He has competed in numerous triathlons and Iron Man events. However, this time he will be competing the event for fun, rather than for a time. He has been unwell and had not intended to take part in the race.

Mr Stride has approached businesses for sponsorship and some are supporting his appeal.

"But if there are any businesses that wish to be a major sponsor, I can put their logo on my bike, helmet and body while I race."

Mr Stride is the aquatics coordinator and a lifeguard at Baywave, which is operated by Tauranga City Aquatics Ltd.

For more information visit Facebook and search for Tinmankini or email Mr Stride on mark.stride@tcal.co.nz.