'A Zodiac boat carrying six passengers and two expedition staff overturned near shore, tragically resulting in two fatalities,' Quark said in a statement provided to Seatrade Cruise News.
Caused by a breaking wave?
'The weather conditions were light winds and smooth sea state, and indications are the accident was caused by a breaking wave. The other four passengers and two staff are recovering under the care and observation of our doctors and medical staff on board,' the statement continued.
The incident occurred near Cape Lookout, Elephant Island, Nov. 15.
Back at Ushuaia
World Explorer returned to Ushuaia on Friday.
'We are in close contact with the next of kin and our priority right now is supporting them, our passengers and crew while we investigate further,' Quark said.
'We will continue to work with, and offer our assistance to, those involved during this difficult time, including full cooperation with the relevant authorities.'
Quark, a seasoned expedition cruise operator with three decades of polar experience, regularly charters World Explorer.
The 2019-built, 1B ice-class vessel has capacity for up to 172 passengers.