Arctic Canadian Diamond will trial underwater crawlers to extract diamonds from its open pits at the Ekati mine in the Northwest Territories, Cabin Radio reported Arctic chief executive Rory Moore as saying.

Moore was speaking at the NWT Geoscience Forum this week.

"As we go deeper into those ore bodies, the value does not support continued mining using conventional techniques," he said. "We needed a method that we could mine at a high tonnage but at a measurably lower cost in order to keep Ekati viable."

Arctic Canadian will trial the underwater crawlers in 2023 and 2024 at the flooded Lynx pit at Ekati. Further tests will continue at the Sable pit from May 2024, to coincide with the end of conventional mining at Sable.

Open-pit mining at Point Lake will begin in 2023 pending approvals. Arctic is considering eventually flooding Point Lake to use the crawlers for mining.

"Point Lake will be the last of the conventional mining pits we do," Cabin Radio reported Moore as saying. "Once the Point Lake pit is completed, the operation at Ekati will be 100% underwater remote mining." The use of the technology could extend Ekati's mine life for many years, he added.

The crawlers will be placed on four tracks to cross the bed, and will use biodegradable hydraulics to minimise pollution in case of failure.

Previous Ekati owners BHP Billiton and Dominion had trialled the underwater technologies in 2009 and in 2013.

Arctic Canadian acquired Ekati from Dominion in early 2021.