This was an east-west route running in Downtown Vancouver connecting Yaletown–Roundhouse and English Bay in the West End. Service ran daily every 15 minutes. It was part of the Frequent Transit Network (FTN), with service provided every 15 minutes or better throughout the day, seven days a week for 15 hours or more.
Eastbound trips departed Morton Avenue & Beach Avenue heading east on Morton, south on Denman Street, east on Beach Avenue, north on Howe Street, east on Pacific Street becoming Pacific Boulevard, and north on Davie Street to Davie & Mainland Street.
Westbound trips departed Yaletown–Roundhouse Station from Davie Street & Mainland Street heading west on Davie, south on Homer Street, east on Drake Street, west on Pacific Boulevard becoming Pacific Street, south on Howe Street, west on Beach Avenue, north on Jervis Street, west on Beach Avenue, and east on Morton Avenue to Morton & Beach Avenue.
September 2004 - Service introduced as C21 Yaletown/Burrard Station/Beach, replacing portions of the 1 Beach/Burrard Station and providing two-way service along portions of the former 1 route.[1] Service ran every 10–15 minutes daily, with peak hour service running to/from Burrard Station via Yaletown. Beach terminus located at Davie Street & Bidwell Street. Service was interlined with the C23 Yaletown/Davie
September 2005 - Route became bike rack equipped
December 2005 - Routing in Yaletown revised due to Canada Line construction and the closure of Davie Street between Hamilton Street and Pacific Boulevard. Introduction of extended evening service on Fridays and Saturdays, extending operation hours from 7 p.m. to 9 p.m. with service every 15 minutes
Yaletown terminus moved to Drake Street & Pacific Boulevard
Peak hour extension routing to Burrard Station revised to go via Drake, Seymour, Davie then regular route. Return trips via regular route, Davie, Richards, Drake
September 2006 - Service extended to Main Street Station for off-peak trips[2]
January 25–February 28, 2010 - Vancouver 2010 Olympic service: Service between Yaletown–Roundhouse and Main Street–Science World discontinued due to downtown pedestrian corridors and BC Place & Canada Hockey Place venue security zones[3]
March 1–13, 2010 - Vancouver 2010 Olympic service: Service between Yaletown–Roundhouse and Main Street–Science World resumed routing via Pacific, Cambie, Pender, Abbott, Keefer due to BC Place & Canada Hockey Place venue security zones[4]
September 2010 - Peak hour service to Burrard Station discontinued.[5] All trips revised to start at Main Street Station except for alternating trips during AM peak hours, which started at Davie Street & Pacific coming off a C23 Yaletown
December 2013 - Interlining with the C23 ended due to different service requirements of the two routes. All service between Yaletown and Main Street becomes part of route C23 as the C21 is revised to run between Yaletown and English Bay only. New around-the-block loops introduced at Yaletown and English Bay and the Beach terminus is revised to Morton Avenue & Beach Avenue
December 2016 - Service discontinued and merged with the C23 to simplify Community Shuttle service in the downtown core and to become the 23 Main Street Station/Beach[6]