Whitlock and Douglas, with son Hunter, moved back to New Zealand last year after the couple spent four years running The Beach Bar near Port Vila in Vanuatu with 30-staff.
"It was a really big show," Whitlock says. "But in the end I was pining for home."
So the family moved back to Taupō where Whitlock grew up.
"[But] there wasn't much community spirit there - it was all shiny and new so we started looking around."
Whanganui was one of those places and they looked at several options, including starting a business from scratch.
"We came in here for a coffee and thought 'neat, this is a great place', carried on our merry way and a couple of weeks later The Citadel popped up for sale," Whitlock says.
"Sometimes things just fall into place and reiterate that it's meant to be. We really feel like The Citadel was meant to be.
"It just ticked all the boxes. Here we are in small town coastal New Zealand with all the community vibe starting to happen, with a neat business on offer, great schools for my son.
"So we sold the house and made a huge life call and moved to Whanganui. We're here for the long haul.
"I haven't met an unfriendly person in Whanganui yet. Everyone's been friendly and welcoming - that's another reason we love this place."
Whitlock says he and Douglasare excited to see what they can do with their own business.
"This is our first ownership of a food and beverage business but I've worked 30 years in the game, so it's our time to own and shine," he says.
"I think it's a perfect time to come in. It's an opportunity to take what the guys have done and find out what Whanganui folk want and provide it.
"It is a great time, the hard work's been done, the success has been there and it just takes a fresh pair of legs to take it to a new place and that's hopefully what we'll do.
There is no plan to make drastic changes in the short term, Whitlock says.
"In the first little while, no, we're not going to change an thing."
The Citadel opened late in 2016 and formed a key cog in the Castlecliff Rejuvenation Project.
Its first owner Charlotte Melser announced last September she was pregnant with twins and was putting The Citadel on the market.
She worked with the new owners in the lead up to this month's handover.
"Charlotte will always be the matriarch of The Citadel and we're the new prince and princess," Whitlock says.
He enjoys the way The Citadel has been tied to a community and says there was a similar spirit in Vanuatu.
A few weeks after his family moved to Vanuatu in 2015 Cyclone Pam devastated the island nation and sparked a community response involving the bar they ran.
"It just tore the place apart," he says.
"I flew Roxi and my son out and stayed and hunkered down and awoke to just chaos.
"But in hindsight that was the catalyst that really bonded us with our village because we did a massive campaign and ended up building about eight houses for our staff and their families."