BC Ferries vessel Spirit of Vancouver Island passes between Galiano Island and Mayne Island while travelling from Swartz Bay to Tsawwassen, B.C., on Friday Aug. 26, 2011. (Darryl Dyck / THE CANADIAN PRESS)

An "extreme weather system" making its way onto B.C.'s South Coast has prompted dozens of ferry cancellations.

BC Ferries called off the majority of Tuesday's scheduled trips between the mainland and Vancouver Island, citing safety concerns for passengers and crew.

"We don’t take the decision to cancel sailings lightly, as we know customers rely on us to get to their destinations. We will resume service as soon as it is safe to do so," reads a travel advisory on the BC Ferries website.

"We appreciate your patience and apologize for any inconvenience experienced as a result of these cancellations."

People with reservations on the affected sailings will have their reservation fees automatically refunded.

Several sailings have also been cancelled between Tsawwassen, Nanaimo and the Southern Gulf Islands.

Environment Canada has issued wind and rainfall warnings for Metro Vancouver, forecasting winds of 70 km/h to reach the coast around noon Tuesday before easing off in the evening.

The weather agency has cautioned the wind could cause "damage to buildings, such as to roof shingles and windows," as well as downed tree branches.

Travellers can check the BC Ferries website for the latest information on sailing cancellations.