The latest controversy regarding Casco Bay Lines should be no controversy at all.

When it comes to how the transportation district should respond to the offer of a new $5.5 million boat — which the trustees applied for and won in a competitive national grant program — they should just say yes.

The new boat would replace a 37-year-old vessel that is nearing the end of its useful life. The old boat, the Island Romance, doesn’t meet current safety or handicap accessibility standards, requires expensive maintenance and is tied up to the dock for much of the year.

The replacement would be another boat built on the design of the 5-year-old Aucosisco III. Although it costs more to run a two-engine boat like the Aucosisco than the one-engine Island Romance, the switch would save the ferry service money by reducing the use of the Maquoit II, the fleet’s biggest fuel hog.

And most importantly, this upgrade would occur with 100 percent federal financing, putting no extra pressure to raise prices on tickets bought by islanders and their visitors.

This is not compelling enough for critics, however. Some argue that what the fleet needs is another car ferry to serve Peaks Island. Others claim that Casco Bay Lines should have smaller, faster boats. They say that the decision to apply for a new ferry was driven solely by the availability of federal money, and there was no time to go through a deliberative design process because projects had to be “shovel ready” to be eligible for the program.

It’s true that a visioning process that involved the public could have come up with a different design than the one that is going out to bid.

But there is no guarantee that a car ferry or a small boat would have been the choice, either. Casco Bay Lines has an elected board of trustees, and a majority of its members still think that accepting a new boat is the right thing to do.

When evaluating their decision, it would be wrong to compare the proposed new boat with an imagined alternative. The question is whether the district is better off with this federally funded boat or without it.

If it’s true that accepting the new boat would avoid future operation costs without adding any debt service to the budget, it’s hard to see why there should be any controversy.