An absolutely amazing form of fishing was covered in 1920 by both Popular Mechanics and The American Angler. Written by John Edwin Hogg, the article relates the following method of submarine fishing:
The boats make frequent practise trips between Los Angeles and Santa Catalina Island. The water in this area averages around ninety feet in depth, and is one of the finest fishing-grounds of the Pacific coast. Frequently the boats dive to the bottom, and lie there with their motors shut off while practicing submarine signaling, torpedo-tube routine, and the like.
The upside down fishing is done in a very simple manner. Prior to making a dive the men arrange their lines on the deck rails of the submarine. The hooks are baited, and are strung out on the decks to be carried upward when the boat dives by a float attached near the hook. Since any fish that takes the bait cannot be removed until the boat comes to the surface, the lines are fastened to the deck rail by coil springs. This practically eliminates the chance of losing the fish by its breaking the line or tearing the hook out of its mouth. Thus the baited hooks 'dangle upward' when the submarine is resting on the sea-bottom — then along comes a fish, swallows the bait, and snags himself.
This method of submarine fishing was given a try-out recently by an electrician aboard the submarine H-5. He baited four lines prior to making a dive, and when the boat came to the surface he had three yellowtail, weighing twenty-four, twenty-eight, and thirty-two pounds respectively. A fourth fish had taken the bait, but got away.
Incredible. I would imagine it would be a very effective way of fishing!
-- Dr. Todd