This spreadsheet dataset contains information on boat-based surveys of alcid marine birds between Sidney, BC and Victoria, BC from November 2015 to August 2019. The marine birds species surveyed in this dataset are the Rhinoceros Auklet (Cerorhinca monocerata), Common Murre (Uria aalge), Marbled Murrelet (Brachyramphus marmoratus), Pigeon Guillemot (Cepphus columba), and Ancient Murrelet (Synthliboramphus antiquus). The study area is adjacent to major shipping lines, ports, marinas, and includes protected areas such as the Sidney Channel Important Bird Area, the Shoal Harbour and Victoria Harbour Migratory Bird Sanctuaries, and Chain Islets Ecological Reserve.