Park Canada has resumed what it says is the biggest and most complex underwater archaeological undertaking in Canadian history – the exploration of Sir John Franklin’s 19th-century British expeditionary ships HMS Erebus and HMS Terror.

Franklin set sail from England in 1845 on a Royal Navy search for the fabled “North-west Passage” across what is now Canada’s Arctic territory. The ships were lost for nearly 170 years but, acting on reports from local Inuit people, Erebus was discovered in 2014 and Terror two years later, as reported on Divernet.

Now that seasonal weather conditions allow, Parks Canada’s underwater archaeology team has set out for the region of Nunavut aboard its newest research vessel, the David Thompson.

On the Terror they aim to focus on 3D structural mapping, and exploring the interior of the wreck using an ROV with an HD point-of view camera.

On Erebus the plan is for scuba divers to concentrate on excavation of strategic areas including the officers’ cabins and lower deck, where Parks Canada believes that thousands of artefacts will be found.