Built in 1975 by Vito Steel Boat and Barge of Delta, BC, it worked for Canadian Marine Drilling in the Beaufort Sea as Supplier II and Canmar Supplier II until 1998 when it went to the North Sea as Rem Supporter until 2005 and Thor Supplier until 2012. (It was also extensively modified.)
When Atlantic Towing Ltd acquired the boat they initially named it Atlantic Birch II. Atlantic's harbour and coastal tugs are typically named for trees and their offshore tugs are named for birds. Since the boat was assigned to the offshore, it was soon renamed Atlantic Tern.
Although fitted with engines providing 7,040 bhp, it seldom needs all that power. It does carry small amounts of supplies but spends most of its time in offshore standby mode at the Deep Panuke gas field off Sable Island.
Sailing for the same destination at the same time was Siem Commander, followed soon after by Maersk Mobiliser (not pictured).
The wells in the field are currently being capped and the structures removed by Heerema's giant crane ship Thialf It will load the scrap material aboard company barges which will be towed to the UK by company tugs.