386 PHYSICAL CONDITIONS OF 



Arran, Kintyre and Ayrshire are all connected by a ridge, the water on 

 which is nowhere more than 25 fathoms deep, and in many places consider- 

 ably less. Numerous small islands, the most prominent of which is Ailsu 

 Craig-, rise from the Plateau. An upheaval of 150 feet would entirely 

 exclude the sea and convert the Clyde Sea-area into one great fresh- water 

 lake and half a dozen small ones. 



The Arran Basin consists of two deep troughs closely embracing the west 

 and east of Arran, which unite at the north of that island, and the single 

 hollow runs straight up Lower Loch Fyne to Otter Spit, the whole having 

 the form of the Greek letter A. The western limb, 30 miles long, occupies 

 Kilbrennan Sound, and has a maximum depth of 84 fathoms. The eastern 

 limb is in the region usually known as the Firth of Clyde, and it runs on 

 continuously with the northern or central limb, the two being traversed for 

 50 miles by one depression, which, with a depth exceeding 50 fathoms, runs 

 from off Pladda, in the south of Arran, to off Kilfinan, near the head of the 

 Basin at Otter Spit. This depression lies near the Island of Arran and 

 shoals gradual!} 7 towards the great sweep of shallow water along the Ayr- 

 shire coast. The deepest area is a narrow trough continuously over 80 

 fathoms in depth, which runs for 27 miles from a line between Corrie in 

 Arran and the south point of Bute to off Stonefiekl, north of Tarbert. In 

 this trough the deepest depression in the Clyde Sea-area is found off Skate 

 Island, where a hole only a few hundred yards in diameter has a depth of 

 107 fathoms. Two short branches of the Arran Basin project north- 

 eastward, one between Bute and the Cumbraes, the other up the western 

 arm of the Kyles of Bute. The sea north of Arran where the eastern and 

 western branches of the basin unite is known superficially as Inchmarnock 

 Water, while the central branch running up to Otter Spit is popularly 

 included in Loch Fyne, or is more accurately called Lower Loch Fyne. 



Upper Loch Fy?ie, which is always meant in this notice when " Loch 

 Fyne " is referred to without qualification, is barred off from the Arran 

 Basin b} r the shoal at Otter, which rises to within 15 fathoms of the surface 

 in mid-channel. The Otter Spit, curving out from the Cowal shore, 

 restricts the entrance of Upper Loch Fyne to a breadth of f mile, except 

 at high tide, when the spit is covered, and the breadth expands to 1| miles. 

 Inside Otter Spit there is a stretch of 7^ miles to Minard Narrows, with a 

 mean depth along the axis of 31 fathoms and 35 fathoms as its maximum, 

 which has been termed the Gortans Basin. At Minard a group of islands 

 splits Loch Fyne into two narrow channels, which are 12 and 18 fathoms 

 deep respectively. Beyond Minard the bed of Upper Loch Fyne deepens 

 gradually to 40 fathoms off Furnace, and then abruptly to 60 fathoms, the 

 greatest depth being 75 fathoms, off Pennimore Point. 1 



The deep channel runs up Loch Fyne to beyond Dunderawe, the branch 

 known as Loch Shira being only a shallow bay. The distance from Minard 

 to the head of Loch Fyne is 18^ miles, and the breadth of nearly a mile 

 diminishes above Inveraray, the loch gradually narrowing towards the head, 

 where it is less than j mile wide, while the hills bordering it become higher 

 and their slopes more steep. 



The Dunoon Basin runs, north-eastward from the Bute Plateau, which bars 

 the short north-eastern branch of the Arran Basin, and pursues its way in 

 a straight line up Lower Loch Long to the entrance of Loch Goil, a distance 

 of 20 miles. The mountainous peninsula between the Dunoon Basin and 

 Loch Fyne is known as Cowal, and is trenched by a series of inlets on its 

 south-eastern side, all running nearly N.N.W. towards Loch Fyne, and 

 most of them occupied by sea-lochs, which give to the Cowal shore of the 



1 I have searched repeatedly and very carefully for the depth of 82 fathoms marked on 

 the Admiralty Chart at this position, and am satisfied that 75^ fathoms is the greatest 

 depth which actually exists. 





