Salmon lakes, as a rule, are large tracts. One feels rather at sea on a first visit to Loch Tay, or to Loch Ness, or to Lough Derg; even smaller lakes present a problem. Where are you to begin, and whither go ? Gillies acquainted with the water have no doubt. They will keep pretty close to the shores, and skirt round islands. That is not wrong. Many salmon do certainly lie near the land. It is there that most of the rises are. I am not sure, however, that this suggests a complete answer to our question. Salmon do not shun the deepest pools in a river, some of which are much deeper than the margin of a lake. Indeed, very deep pools on a river are favourite haunts of the fish. Nevertheless, it is generally assumed that they frequent the shallower parts of a lake exclusively. This belief might be accepted without suspicion if it were not that a similar belief about the habits of trout is open to question. Trout are sought and found all over Lochleven; but Lochleven is exceptional. Whilst the whole of it is comparatively shallow, most lakes are shallow only at the sides, and on these it is along the shores that the boats of the trout fishers drift. It is thought that to go farther out would be a waste of time and effort. That, I admit, would be the case in a breeze sufficiently high to tip the waves with spray. I have tried often enough to be sure that in such weather, or in rougher weather, you cannot, on the deep parts of a lake, expect the trout to come at flies. When the wind has fallen, however, and the water is calm, you will, in summer, if the other atmospherical conditions are favourable, see, from the marks, that fish are rising all over the lake. Where were the fish when the winds were out ? There are two possibilities. It may be that fish were then, as now, all over the lake, in the deeps as well as in the shallows, but that, for some reason not yet discovered, those in the deeps do not rise when the water is rough. It may be, on the other hand, that the fish spread out all over the lake only when the weather is dead calm or nearly so. A friend who habitually lives by the side of a fine lake advances this view. He says that the trout, usually gathered in the shallows all round the water, go out hunting the flies in times of calm, and he explains the lack of sport far from the land at other times by the simple belief that the fish are not then there. This understanding does not seem sufficient. If trout follow the flies as trade follows the flag, it is in time of wind that we should find them far out on the lake. Most of the flies are aquatic, born either in the comparatively shallow parts of the lake, most of which are along the shores, or in the tributary streams. Unless they wander when the atmosphere is calm, it must be when there is wind that they go forth upon the water. I do not think they wander. I think that when out on the deeps they have been blown thither. This thought seems to be justified by the fact that very soon after putting off from the shore you are quit of that exasperating insect, the Highland Midge, which during calm weather in spring and early in summer is found in stinging myriads where land and water meet. It seems probable, then, that throughout the period of the year in which the surface of the whole water is equably warm, the trout, though in wind they rise in the shallows only, are distributed all over the lake. If this be so, why should it be supposed that the salmon, which are of the same race, are not similarly dispersed ? I can imagine an answer. "If salmon lie about all over the lake, as trout sometimes do, why are they never seen rising there when the water is calm ?" This looks convincing; but it is not so. We cannot with certainty distinguish between the rise of a salmon and the rise of a trout. In the case of every salmon that has honoured a fly of mine, the rise, as far as one's sight could tell, was just like that of a trout. Hand, arm, and nerves usually knew better in an instant; but the vision was uninformed. It is just possible, then, that some of the spreading rings on the surface of a calm lake notify rises of salmon. If these fish ever do take a real fly, it is morally certain that they take it quietly. To say that they often leap into the air would be beside the point. When they leap into the air salmon are " rising to themselves," and not, as far as can be seen, at anything to snatch. When they rise at a fly they are much less acrobatic. Often, indeed, they take it without breaking the water. All the salmon with which I myself have had to battle in a lake have come on not far from the shore; but that may be only because, time being precious, I have usually sought sport where some fish were known to be, instead of experimenting where others might possibly be. A consideration supporting the surmise that some salmon may be far out while others are close in occasionally suggests itself early in the period of the spring fishing. Sometimes the lake is covered by sheets of ice, sheets that were once a single sheet, separated by channels of open water. It being impossible to fish through the ice, any salmon that comes on does so, of course, in one of the channels, which as often as not is a good way from the shallows by the shore. As it is probable that the fish prefer to lie where the water is not ice-bound, this is not conclusive evidence as to the locality of their haunts; but it is worth mentioning. It shows that sometimes at least the fish do lie in the deeps.
Even if it were certain that they did not, we should frequently err by fishing along the shores exclusively. Casually looking at a lake, which is almost geometrically perfect in superficies, and seems to deepen from the shore outwards according to a gradation roughly regular, we are apt to suppose that it is symmetrical below. It is not. Its inner configuration is not like that of a bowl. It is irregular. If the water were miraculously removed, it would be seen to be the configuration of hill and dale. Here and there would be an extensive plateau. There is one, for example, in the middle of Loch Lubnaig. Thus, it is not only near the shores in every case that a lake is shallow. In many cases it is shallow, or comparatively so, far out. Where it is, as above the great bank in Loch Lubnaig, salmon as well as trout habitually lie.
Here and there we come upon a lake that is not exactly as it used to be. Man, or some process of Nature, has raised the level of the land over which the water goes at the outflow. The depth of the lake has been increased. The water has expanded on all sides. In particular, it has pushed up at the head of the lake. Part of the inflowing river, perhaps a long part, has been submerged. Peer into the lake as you drift down from where the river now merges into the still water, and you will see the channel. It is a distinct groove through what bears traces of having been something in the nature of a meadow. Even, it may be, there is still grass on both sides of the channel. That is a good place over which to fish. If there are any salmon in the lake, some of them will be there. It is the path of their ancestors from time immemorial. Hereditary instinct as to locality is as strong in salmon as it is in birds.
Although some salmon certainly lie along by the shore, it would be a mistake to suppose that any bit of water near the land is as good as any other. A few years ago, having set out on Loch Nell, in Argyllshire, I wished to go to the south shore. There, near the end of the lake, I saw a long ledge of high rock. It looked, I thought, the very place for the sea-trout I expected to catch, and for the salmon which were possible. Quietly the gillie protested. " They'll no' be there, I'm thinkin'," said he. " Salmon and sea-troot dinna lie muckle whaur there's rocks or trees. They like the open pairts. It's nearly aye jist opposite a bare bank, and no' a vera high bank, that ye get them." That was a striking remark. I had thought of trout, in the conventional way, as preferring the shady streams and pools, and still more assuredly of salmon as making their haunts in as rugged scenery as they could find ; but on Loch Nell I realised, by repeated experience, that what the gillie said was true, and I have since perceived it true in every other lake I have visited.