Stena Line is moving its operations up the coast to a new deep water port just north of Cairnryan.
The company's Irish Sea route director Paul Grant said the development secured a future in Loch Ryan that it might not have had without the move.
However, local historian Jack Hunter said it was a major milestone which would leave a void in the town.
The development took more than a decade to plan and deliver and has been project-managed by Stena's Alan Gordon.
It is designed to cut costs and reduce crossing times to Northern Ireland.
"It represents £200m worth of investment by Stena Line in Loch Ryan port and two new ships," said Mr Gordon.
"It shows that there is a future here for Stena Line - it means that Stranraer will benefit because the majority of people that work on the ferries live in Stranraer."
The company proposed relocation out of Stranraer several years ago and subsequently entered into talks with rivals P&O about sharing expanded facilities in Cairnryan.
However, in 2007 those plans were dropped due to the prohibitive costs involved.
Two years later it reverted to its original plans and decided to go it alone with the move.
Mr Gordon admitted there had been a "few false dawns" along the way but added that he believed it was the "right thing to do".
Mr Grant said it was the "right facility in the right location" and now had the "right ships" to take the business forward for decades to come.
"The route has been losing money and that is the harsh reality of it," he said.
"We couldn't sustain the route, potentially.
"We have had to make this investment to make this route profitable and give us all a future and keep the jobs and so forth in this area because that is what's important."
Mr Hunter said the end of the ferries was a moment of "psychological significance".
"This is a link that has been in operation for more than 150 years," he said.
"People are used to seeing the ferries coming and going - it gives them a feeling they are connected to other places.
"With no boats coming in I think it will give a feeling of isolation, a feeling of being at the end of the line."