For safety of marine mammals and your boat, you should always watch for blows from whales, aggregations of birds over schooling fish (whale food), and vessels flying the "Whale Warning Flag".
Canadian Marine Mammal Regulations. Generally boats must stay more than 100 m away from all whales, dolphins and porpoises, and 200 m from Killer Whales, marine mammals with calves, and when in a resting position. In 2021, a mandatory 400 m distance from Killer Whales in southern BC coastal waters. To protect whales within 1 km, you may also slow down, turn off echo sounders and stop fishing.
The whale warning flag (black whale tail on red and yellow ball) can be waved by hand to warn other boaters.
Marine Education & Research Society (MERS) is a registered charity in British Columbia dedicated to promoting conservation and understanding of marine ecosystems.
Vessels flying a yellow "MML" (Marine Mammal License) pennant are licensed by Fisheries and Oceans Canada (DFO) to undertake research on marine mammals. They may approach marine mammals within regulated limits for research purposes. Other boats must stay away.