Firth of Tay
The Firth of Tay (Scottish Gaelic: Linne Tatha) is a firth in Scotland between the council areas of Fife, Perth and Kinross, the City of Dundee and Angus, into which Scotland's largest river in terms of flow, the River Tay empties. The firth has a maximum width of at Invergowrie.
Moray Firth
Basically, the Moray Firth is of tectonic origin, related to the Great Glen Fault. For some time during the glaciation, the whole of nowaday's Moray firth was a huge glacier. Nevertheless, the inner Part and its side-inlets, Cromarty Firth and Dornoch Firth, are true fjords themselves. Though there is a reasonable tide with mean tide ranges of about three metres (ten feet), only part of the rivers draining into the bay have estuaries. Masses of sediment from the adjacent mountains have formed spits around several mouths. Those of River Ness and River Carron have significantly narrowed the fjords they enter.