Now he says he is excited to be joining HBRIC's ranks, because the company could be one of the biggest "growth engines" for Hawke's Bay jobs and future generations.
"I live here, and I love this place, and there are only a few significant businesses with the opportunity to really add value as a director and this is one of them."
Meanwhile, however, reviews are under way relating to HBRIC's two major investments - the Ruataniwha Water Storage Scheme (RWSS), and the Napier Port respectively.
When asked if he felt he was entering HBRIC during a period of uncertainty, Mr Tremain said there would always be "some legacy challenges or legacy opportunities" when entering a business in a leadership role.
"It is a complex issue from an environmental point of view, an economic and financial point of view, I'm looking forward to the challenge."
In a meeting hours before the directors were appointed last week, some regional councillors had questioned whether HBRIC had a future, depending on the outcome of the two reviews.
In response to this, Mr Tremain said his understanding was that the council had made a "clear decision" to retain the investment company.
"That's the understanding that I've entered into this role, but clearly HBRIC has to prove its worth," he said, adding he hoped there were several years in which this could be done.
"Ultimately unless it adds value it doesn't have a place, we've clearly got to demonstrate . . . the value proposition better than possibly has been done in the past."
Fellow new director Mr Randell said the region was on a "real boom", and he was excited to be involved with future plans for environmental, and regional development.
The former All Black is also a director of other boards including the Kahungunu Asset Holding Company - Ngati Kahungunu has previously battled against the RWSS, even going to the Environment Court and a board of inquiry over it.
When asked if he felt there was any conflict between his Kahungunu and HBRIC directorships, Mr Randell said he was not conflicted, but "open-minded".
"To be fair HBRIC's not just about the dam, even though it's a big part of it," he said, adding he felt the two companies could be "quite complementary".
"I'm looking forward to being involved, certainly when it comes to the dam, seeing the information for myself and making the decision that I think is best," he said.
He added having a Ngati Kahungunu voice at the HBRIC table could help with engagement.
Yesterday Mr Druzianic shared the excitement of his new co-directors, saying being involved in HBRIC was a "great opportunity" to contribute to the future of Hawke's Bay.
He felt HBRIC was "coming into a new era", which he would bring considerable financial and commercial experience to.
The Moore Stephens Markhams managing director is also a member of the Hawke's Bay District Health Board and independent chairman of Hawke's Bay Wine Country.