The lough is almost fully enclosed by the Ards Peninsula and is linked to the Irish Sea by a long narrow channel at its southeastern edge.
The main body of the lough has at least seventy islands along with many islets (pladdies), bays, coves, headlands and mudflats.
[4] The rocky and boulder shores toward the south of the lough are dominated by the seaweed knotted wrack Ascophyllum nodosum.
Three quarters of the world population of pale bellied brent geese spend winter in the lough area.
[10] In 2007 Strangford Lough became home to the world's first commercial tidal stream power station, SeaGen.
[11][12][13] In 2008 a tidal energy device called Evopod was tested in Strangford Lough near the Portaferry Ferry landing.
The event was attended by 50 clubs from Scotland, England, Northern Ireland, the Netherlands, The United States, Canada and Tasmania.
[17] The subsidised public service carries both passengers and vehicles, and operates at a loss of more than £1m per year but is viewed as an important transport link to the Ards Peninsula.