Statistics have been published to show that practically the entire commerce of the world sinks in every twenty-five years. In the present war the rate of sinking has been, of course, enormously accelerated, and millions of tons of ships have been sunk, with billions of dollars' worth of cargo. Many of these vessels were sunk in the North Sea or the English Channel, where the water is comparatively shallow, and where many of the cargoes can undoubtedly be recovered with the proper apparatus. The loss of ships in peace times is such a common occurrence that little attention is paid to them except when their loss is accompanied by great loss of life, as was the case with the _Titanic_, the _Monroe_, the _Empress of Ireland_, or the _Lusitania_. There are therefore great opportunities for devices of this nature to operate profitably. Another use to which the submarine may be put is the recovery of shellfish from the sea bottom. For such work as this adaptations of the submarine vessel are well fitted. A submarine vessel of the "Lake" bottom-working type has been designed and is now being built for the location of and the recovery of shellfish on a large scale. Shellfish abound on both the Atlantic and Pacific coasts in great quantities. They are about the most delicious and nutritious food known to man. The most common shellfish are the oyster, the round or hard-shell clam, the long-neck or soft-shell clam, the scallop, and, on the Pacific coast, the abalone, which is valuable both for its mother-of-pearl shell and its meat, which is a great delicacy, the most of which is sent to Japan, either dried or canned. My own sea-bottom investigations, combined with the sea-bottom investigations of the United States Fish Commission, have led me to the conclusion that edible shellfish abound along our coast in such great quantities that they can become an important rival to our meat-growing and packing industries, provided the proper apparatus is used for their recovery. I have, when "wheeling" along the bottom, found beds of the round or hard-shell clam in such great quantities that there must have been thousands of bushels to the acre. This was in waters too deep to be recovered by the usual clammers' apparatus. It is impossible to dredge for the soft-shell clam, as the shell is too delicate, and to pull them out of their bed would crush them. The abalone attach themselves to rocks, and it requires considerable force to break their hold, so there is no known means to recover them with surface ships.