272 
BATHYMETRICAL SURVEY OP 
The superficial area is nearly 15 square miles, which places Loch Awe 
third in this respect among the Scottish lakes, being exceeded only by 
Loch Lomond with 27 J square miles, and Loch Ness with 21 J square 
miles. 
Loch Awe was surveyed on May 9 to 22, 1903, and during this time 
the level of the water varied to the extent of about 2 feet, the highest 
level, as measured from bench-mark, being 117*9 feet above the sea, 
and to this level all the soundings on the map have been reduced. It 
is interesting to note that this elevation is identical with that determined 
by the naval officers during their survey in 1861, so that the depths 
shown on the Admiralty chart are strictly comparable with those shown 
on the Lake Survey map now published. Thus the maximum depth 
given on the Admiralty chart is 51 fathoms, or 306 feet, four soundings 
at this depth being indicated between 4 and 5 miles from the head 
of the loch, while the maximum depth recorded by the Lake Survey is 
307 feet, two soundings being taken at this depth in a similar position. 
As regards maximum depth, Loch Awe is exceeded by fourteen Scottish 
lakes, and as regards mean depth, which is estimated at 105 feet. Loch 
Awe is exceeded by nineteen Scottish lakes. The volume of water in 
Loch Awe is estimated at 43,451 millions of cubic feet, which is exceeded 
by only four Scottish lakes (Lochs Ness, Lomond, Morar, and Tay). 
The floor of Loch Awe is uneven, as will be seen from the longitudinal 
section along the axis of maximum depth placed at the foot of the map. 
Some of the cross-lines of soundings also show irregularities of the bottom. 
The 50-feet contour-line is continuous, and coincides, on the whole, with 
the outline of the loch, extending nearly from end to end. The 100-feet 
contour’ encloses three separate areas — (1) the largest extending from 
little more than a mile from the head of the loch to near the islands at 
the junction of the arm at the Pass of Brander, a distance of about 18 
miles ; (2) the second, extending from about half a mile from the entrance 
of the river Orchy into the arm at the Pass of Brander, is over 4 miles 
in length ; and (3) the smallest, based on soundings in 125 and 128 feet, 
in the Pass of Brander, separated from the second area by a depth of 
86 feet. The 200-feet contour encloses no fewer than five separate 
areas : (1) a very small area based on an isolated sounding in 200 feet 
about 2 miles from the head of the loch, separated from the second area 
by a depth of 195 feet; (2) the principal area, including the deepest 
water in the loch, about 5 ^ miles in length, extending from the entrance 
of the Karnes river to little more than 2 miles from the head of the loch ; 
(3) an area about 1 J miles in length at the junction of the main loch with 
the arm at the Pass of Brander, having a maximum depth of 249 feet ; 
(4) a small area, based on soundings in 207, 217, and 230 feet, lying 
between the islands of Innis Chonain and Eilean Beith ; and (5) a small 
area with a maximum depth of 234 feet, off Rudha Dubhairt, about 1^ miles 
from the entrance of the river Orchy. It is to be noted that the middle 
