Union representative Dave Clark says the Kitsilano Coast Guard Station has already responded to 55 life-threatening calls this year, including nine over the May long weekend.
Vancouver city councillors Geoff Meggs, Tim Stevenson and Kerry Jang expressed outrage that the station was scheduled to be shut down without any local consultation.
The station responds to around 300 calls per year and has an annual cost of $900,000.
Fisheries and Oceans Canada has said the Kitsilano station's calls can be covered by a coast guard station at Vancouver International Airport, but union and city officials say the 30-minute response time would put too many lives in danger.
The union has started a Facebook page called Save the Kitsilano Coast Guard Base, and is urging the public to call on Fisheries and Oceans Minister Keith Ashfield to reverse the station's closure.