It is situated in the Indian Ocean offshore from Fremantle, Western Australia, and incorporates a deep water sea channel.

[1] Gage Roads serves both as a shipping lane and as an anchorage for sea traffic heading towards the seaport of Fremantle.

The area is the most northern of one of four coastal basins formed from the flooding of a depression between Pleistocene aeolianite ridges running north-south, and the subsequent deposition of east-west Holocene banks.

[4][5] At certain times, over 10 ships can be seen anchored in Gage Roads waiting to enter the port of Fremantle.

[6] In the early 1900s, the local boat SS Zephyr regularly took cruises in Gage Roads.