Investigators in Canada have boarded the support ship used to launch the Titan submersible in their bid to understand what caused the vessel's catastrophic implosion.
Flags on board the Polar Prince were at half-mast as it docked in St John's, Newfoundland, on Saturday.
Another boat was seen in the harbour towing the Titan's launch platform.
The Titan was on a dive to the wreck of the Titanic when it broke apart, killing all five people on board.
Locals in St John's gathered around the cannon on top of Battery Lookout at 08:00 (11:30 BST) to watch the Polar Prince return to port. As some passengers disembarked, investigators in hard hats and high-visibility jackets climbed aboard.