Strait of Georgia
Arm of the Salish Sea between Vancouver Island and mainland.
The Strait of Georgia—also called the Georgia Strait or, in French, Détroit de Géorgie—is a section of the Salish Sea. It lies between Vancouver Island and the southwestern mainland coast of British Columbia, Canada, as well as the northwestern mainland coast of Washington, United States. The strait stretches about 240 kilometres (150 miles) in length, with a width that ranges from 20 to 58 kilometres (12 to 36 miles). Together with Puget Sound and the Strait of Juan de Fuca, it forms part of the larger Salish Sea. Because the port of Vancouver sits on its shores and it serves as the southern gateway to the Inside Passage (an Intracoastal waterway), the strait is a key navigation route on North America’s west coast.
At its southern end, the strait is marked by the Gulf Islands and San Juan Islands, while the Discovery Islands cluster at its northern end. The main southern channels—Boundary Pass, Haro Strait, and Rosario Strait—link the Strait of Georgia to the Strait of Juan de Fuca. To the north, Discovery Passage connects it to Johnstone Strait. According to the United States Geological Survey, the southern boundary runs from East Point on Saturna Island through Patos, Sucia, and Matia Islands, then to Point Midgley on Lummi Island. This line touches the northern edges of Rosario Strait (which leads south to the Strait of Juan de Fuca) and Boundary Pass (which leads south to Haro Strait and the Strait of Juan de Fuca).
The strait’s average depth is 156 metres (512 feet), and its surface area covers roughly 6,800 square kilometres (2,600 square miles). At its deepest point, the Ballenas Basin in the centre reaches 420 metres (1,380 feet), located about 15 kilometres (9.3 miles) north of Nanaimo. The Fraser River supplies around 80 percent of the freshwater that flows into the strait, and water generally circulates in a counterclockwise direction.
Among the many islands within the strait, Texada Island is the largest, covering 300.45 square kilometres (116.00 square miles). Other significant islands include Nelson, Denman, Lasqueti, and Hornby.
Historically, the term “Gulf of Georgia” was broader than the Strait of Georgia proper. When George Vancouver mapped the area in 1792, he used “Gulf of Georgia” to describe all inland waters east of the Strait of Juan de Fuca, including Puget Sound, Bellingham Bay, the waters around the San Juan Islands, and the S
- length
- 240 km (150 mi)
- width
- 20 to 58 km (12 to 36 mi)
- mean depth
- 156 m (512 ft)
- maximum depth
- 420 m (1,380 ft) in Ballenas Basin
- surface area
- 6,800 km² (2,600 mi²)
- major freshwater source
- Fraser River (approx. 80%)
- largest island
- Texada Island (300.45 km²)
Lore & Background
First Nations communities have surrounded the Strait of Georgia for thousands of years. The first European exploration of the area was undertaken by Captain Jose Maria Narvaez and Pilot Juan Carrasco of Spain in 1791. At this time Francisco de Eliza gave the strait the name 'Gran Canal de Nuestra Señora del Rosario la Marinera.' In 1792, it was renamed for King George III as the 'Gulf of Georgia' by George Vancouver of Great Britain, during his extensive expedition along the west coast of North America. Vancouver designated the mainland in this region as New Georgia and areas farther north as New Hanover and New Bremen.
The June 23, 1946, Vancouver Island earthquake shocked the Strait of Georgia region, causing the bottom of Deep Bay to sink between 3 and 26 m (9.8 and 85.3 ft). The two busiest routes of the BC Ferries system cross the strait, between Tsawwassen (south of Vancouver) and Swartz Bay (near Victoria) and between Horseshoe Bay (north of Vancouver) and Nanaimo. The Strait of Georgia is known as a premier scuba diving and whale watching location. In 1967, the Georgia Strait inspired the name of Vancouver's alternative newspaper, The Georgia Straight, which has been published continuously since.
Reader's Guide
The Strait of Georgia is a vital waterway on the west coast of North America, serving as a major navigation channel due to the port of Vancouver and its role as the southern entrance to the Inside Passage. Its waters connect the Salish Sea system, linking the Strait of Juan de Fuca and Puget Sound. The strait supports significant ferry traffic, with BC Ferries operating key routes between Vancouver Island and the mainland. Ecologically, the Fraser River provides about 80% of the freshwater entering the strait, and the water circulates in a generally counterclockwise direction. The region is known for scuba diving and whale watching. Historically, the strait was first explored by Spanish navigators in 1791 and later renamed by George Vancouver in 1792. The 1946 Vancouver Island earthquake altered the seafloor in Deep Bay. In 2009, the name 'Salish Sea' was officially adopted as a collective term for the Strait of Georgia, Puget Sound, and the Strait of Juan de Fuca by geographic boards of Canada and the United States, without replacing the individual names. The strait's shores host numerous communities, including Greater Vancouver, Nanaimo, and Bellingham, Washington.
Did You Know?
- The Strait of Georgia is approximately 240 km long and varies in width from 20 to 58 km.
- The Fraser River accounts for roughly 80 percent of the freshwater entering the strait.
- The June 23, 1946, Vancouver Island earthquake caused the bottom of Deep Bay to sink between 3 and 26 m.
- In 1967, the Georgia Strait inspired the name of Vancouver's alternative newspaper, The Georgia Straight.
Frequently Asked Questions
Who is Strait of Georgia?
The Strait of Georgia is a stretch of the Salish Sea bounded by Vancouver Island on one side and the mainland shores of British Columbia and Washington State on the other. Locals and francophone sources sometimes call it the Georgia Strait or Détroit de Géorgie.
Where is Strait of Georgia located?
It occupies the gap between Vancouver Island and the southwestern BC / northwestern Washington mainland coast. Together with Puget Sound and the Strait of Juan de Fuca, it forms the larger Salish Sea.
What are Strait of Georgia's key dimensions?
The waterway runs about 240 km (150 miles) long and spans 20 to 58 km (12 to 36 miles) across. Its average depth is 156 m (512 ft), though Ballenas Basin plunges to a maximum of 420 m (1,380 ft), and the total surface area is roughly 6,800 km² (2,600 mi²).
Why is Strait of Georgia important?
The city of Vancouver anchors its shore, making the strait a vital shipping and trade corridor for the Pacific Northwest. It also acts as the southernmost component of the Salish Sea, linking inland waters to the open Pacific.
What river feeds Strait of Georgia?
The Fraser River dominates freshwater input, delivering approximately 80% of all fresh water that enters the strait. This enormous discharge drives much of the strait's estuarine mixing and supports its productive marine ecosystem.
More in Straits, Channels, And Seas 1-24
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