While the return of an international ferry servicing Portland would be something to celebrate, it may be too early to pop any corks.

It is not hard to be encouraged by the word from Canada that there are five companies interested in reviving ferry service between Yarmouth, Nova Scotia, and New England, and that Portland, because of its proximity, has a leg up on the competition: Portsmouth, N.H., and Boston. But there are still a lot of decisions to be made and they are going to be made in Canada, not here.

For many years Portland enjoyed a relationship with Halifax, at first connected by the overnight ferry Scotia Prince, and then the high-speed “Cat,” which was the original anchor tenant of Ocean Gateway, the $20 million facility built mostly with state money.

It was a surprise to hear that the government of Nova Scotia was dropping its subsidy of the Cat, effectively cancelling service this year. Fortunately, the port has enjoyed a busy cruise ship season, replacing much of the lost tourism.

Ferry companies are reportedly considering Portland, but they are looking at other sites as well. It is also true that a new ferry may not look exactly like the service we had come to know in the past.

Transportation consultant Jeff Monroe, who used to serve as Portland’s transportation director, says economic studies have found that seasonal ferries serving both Bar Harbor and Portland don’t make sense for Nova Scotia. What might work, however, is a single, year-round service that could operate during the winter ferrying trucks.

It’s good that Portland is in the conversation when people talk about reviving the service. But the conversation has a long way to go before we expect to see a ship docking.