The Victoria Joint Rescue Co-ordination Centre says the 67-year-old woman boarded the Sapphire Princess Cruise Ship in Ketchikan, Alaska, but failed to disembark when the ship arrived in Vancouver today.
The centre says it launched a search after getting a call from the U.S. Marine Rescue Coordination Centre in Juneau, Alaska.
A Buffalo aircraft and a Cormorant helicopter, a Hercules aircraft and two Canadian Coast Guard vessels are searching the waters from Vancouver to Port McNeill, off Vancouver Island.
The U.S. Coast Guard also has a search underway in the waters off Alaska.
Police in Vancouver are also investigating.
