He was inspired with the wooden boats idea after seeing them on the Colorado River in the United States' Grand Canyon. He'd also noticed how exhausted some people looked after canoeing the Whanganui and wanted other options for them.
In 2014 Brad Dimock and Andy Hutchinson, both Grand Canyon guides, built him two Briggs-style river dories at a farm near Taihape. The flat-bottomed boats are made of mahogany, white oak and cedar and carry enough gear for luxurious camping.
Mr Megaw says they are beautiful. The Whanganui public will be able to see them on January 24, as part of Vintage Weekend.
The boats were blessed by Ratana apotoro Rehita Puruhe Smith in December, and named Te Whaiau and Okupata. They've had trial runs and make their first commercial trip this week.
The new business needed a Conservation Department concession to take customers camping on conservation land. Iwi input was part of getting the concession, along with practical matters such as safety audits. As the first granted since the Whanganui River Settlement was signed in August 2014, the concession set precedents. Mr Megaw said a lot of liaising with iwi was involved and he found it a really positive experience.
"I thought I knew a fair bit, as every Pakeha New Zealander probably does, but I was challenged fairly early in the piece to realise how little I did know."
He took a trip with young Ki Tai Whanganui River guides and plans to add tikanga (Maori protocol) to the dory operation. He's now also taking a course in te reo Maori and finding out about river history. "We want (the trips) to be more than just pretty scenery."
The two boats hold three or four paying customers each, with a guide to row them. Being wooden they have to avoid hitting rocks and other obstacles and cannot be used when water levels are very low. They are built to handle "really really big water".
The first guides will be Mr Megaw and Doug Lawrence, who also guides in the Grand Canyon.
Trips will be for three or five days.
They will be ideal for older people and those who don't want to paddle or risk a canoe capsizing, Mr Megaw said.
"It's a comfortable experience, but it's still adventurous."