Sinclairs Bay has two primary geological features. Starting at the coastal village of Keiss, running northeast, a stony beach and coastal crags, become cliffs that are increasingly sheer the further north. South of Keiss, the cliffs even out in a large white sandy beach, called Keiss Beach, forming large Dunes of Reiss Beach further south. At Ackergill Tower, the beach again becomes stony and eventually forms into a series of cliffs and crags, further east.
^Gittings, Bruce; Munro, David. "Castle Sinclair". The Gazetteer for Scotland. School of GeoSciences, University of Edinburgh and The Royal Scottish Geographical Society. Retrieved 22 April 2023.
^Gittings, Bruce; Munro, David. "Noss Head". The Gazetteer for Scotland. School of GeoSciences, University of Edinburgh and The Royal Scottish Geographical Society. Retrieved 22 April 2023.