Only a few have significant elevations, e.g. Big Woody Island rises to 50 metres (160 ft) above sea level.

[6][7] Although he established that K'gari was not a peninsula (as was then believed) but an island, he failed to find a navigable channel through the Great Sandy Strait.

[8] Lieutenant Joseph Dayman was the first European to navigate through the Great Sandy Strait on 10 November 1846 in a small decked boat called the Asp.

[10] A complex landscape of mangroves, sandbanks, intertidal sand, mud islands, salt marshes and seagrass beds, the Strait is an important habitat for breeding fish, crustaceans, dugongs, dolphins and marine turtles.

[citation needed] The lower part of Great Sandy Strait was listed under the Ramsar Convention as a wetland of international significance in 1999.

Some 806 km2 of the strait has been identified by BirdLife International as an Important Bird Area because it supports about 120,000 non-breeding waders, including over 1% of the global populations of bar-tailed godwits, eastern curlews, great knots, grey-tailed tattlers, lesser sand plovers, pied oystercatchers, red-necked stints and red-capped plovers, as well as small numbers of the range-restricted mangrove honeyeater.