386 
BATHYMETRICAL SURVEY OF 
The 100-feet basin is about 22J miles in length, the southern 
extremity approaching to within 100 yards from the shore at the 
entrance of the river Tarff, and the northern extremity extending 
into the narrow part of the loch beyond Torr point, approaching to 
within a quarter of a mile from Bona ferry. 
The 200-feet basin is 21| miles in length, approaching to within 
150 yards from the Monastery boat-house slip at Fort Augustus, and 
quite close to the south-western shore off the entrance of the river 
Oich, and extending beyond Torr point on the north to within less than 
a mile from Bona ferry. 
The 300-feet basin is 20| miles in length, extending from less than 
300 yards from the Monastery boat-house slip on the south to just 
beyond Torr point, or IJ miles from Bona ferry, on the north. 
The 400-feet basin is 20 miles in length, distant over a quarter of 
a mile from the Monastery boat-house slip on the south, and about 
three-quarters of a mile from Torr point, or over 2 miles from Bona 
ferry, on the north. 
The 500-feet basin is about 18J miles in length, distant less than 
a mile from the Monastery boat-house slip on the south, and about 
IJ miles from Torr point on the north. The southern extremity of 
this basin differs somewhat from the usual truncate form, partaking 
of a rectangular character. 
The two 600-feet basins are separated by an interval of little over 
half a mile, and are almost exactly equal in length, both of them 
slightly exceeding 8 miles in length. The northern one is distant about 
2 miles from Torr point, and the southern one less than 2 miles from 
the Monastery boat-house slip at Fort Augustus. 
The two 700-feet basins are separated by an interval of nearly 
2J miles, the northern one being nearly twice as long as the southern 
one, and including the maximum depth of the loch — 754 feet. The 
northern basin is miles in length, and distant about 2| miles from 
Torr point, while the southern basin is 3J miles in length, and nearly 
6 miles distant from Fort Augustus. The maximum depth recorded 
in the southern basin was 739 feet near the southern end of the basin, 
while towards the northern end of the basin a depth of 735 feet was 
recorded, the intervening soundings being slightly shallower. 
These details show how extremely symmetrical Loch Ness is in all 
its bathymetrical characteristics. All the contour-lines, except the 
deepest one, approach rather closer to the southern than to the northern 
end of the loch, but in the case of the 700-feet contour this is reversed. 
The shore-slope on both sides of the loch is nearly everywhere steep. 
Gradients exceeding 1 in 1 are of frequent occurrence, and in certain 
places the slope approaches the precipitous. Near the southern end 
of the loch, off the south-western shore at the entrance of the river 
Oich, a sounding in 204 feet was taken about 100 feet from shore, but 
