Because of its depth, Loch Ness is the largest loch by volume of water, with a volume of 7.4 km³. On the other hand, Scotland's deepest loch is Loch Morar (1077 feet). The longest sea loch is Loch Fyne in Argyll (approximately 44 miles long). The longest inland loch is Loch Awe, Argyll (approximately 25 miles long).