There have been strange sightings in Halifax harbour over the years, but like most UFO sightings, there is a simple explanation.
Perhaps a New Brunswick cable ferry* is not immediately identifiable as such (Nova Scotia has several too), but even so cable ferries are not equipped to stray from their normal routes**. And so it is with Woolastook I which normally plies the 0.7 km, 5 minute route from Grand Bay-Westfield to Hardings Point, not too far upstream from Saint John. This time however it is in control of the tug Strait Raven under tow for a refit at Port Hawksbury.
Superport Marine, operators of the tug, have developed expertise in refitting cable ferries, and won the contract for refitting Wollastook I in November 2020 with a bid of $424,637.50. Superport also recently completed the refit of a fleet mate which was delivered back to New Brunswick by the Strait Raven last week.
I believe the tug had a navigational system glitch (possibly radar) and put in to Halifax for repair.
Woolastook I was built in 1980 by Apex Machine Works Ltd of Moncton, and has a capacity of 15 cars. It is owned by the New Brunswick Minister of Transportation and Infrastructure.
Strait Raven is a 500 bhp tug, built in 2013 by Superport Marine of Port Hawksbury.
* Cable ferries have no independent means of propulsion. A hauling engine (like a winch) picks up a cable which runs from shore to shore and winds the ferry back and forth across the river The cable is seldom visible since considerable slack is built in, allowing the cable sit on the river bottom so as not to impede other marine traffic.
** On October 15, 1996, sister ferry F-39 which served the same route took an unscheduled 5 mile, 2 hour drift down river when its cable parted. On board, in addition to the crew was one auto with two adults and a child. The Transportation Safety Board determined that the cable was corroded, and made a number of recommendations, including the installation of anchors on cable ferries.