| 1931 KELLEY Submarine Rescuing Device Patent |
| 1931 GRIESHABER Dry Mine Laying Submarine Patent |
| 1931 SPEAR Rescue Submarine Patent Print Art |
| 1931 SIMPSON Submarine Boat Patent Print Art |
| 1931 GRIESHABER HUGO Submarine Boat Patent Print |
| 1931 PABLO Submarine Patent Print Art |
| 1931 FREDERIK Submarine Mine Layer Patent Print |
| 1931 ANDREWS Submarine Safety Device Patent |
| 1931 ROBINSON Submarine Safety Apparatus Patent |
| 1931 SPEAR Mine Laying Submarine Patent Print |
| 1931 CALIFORNIA SITTON Submarine Patent Print |
| 1931 ROCCO Submarine Rescue Device Patent Print |
| 1931 PEGG Submarine Rescue Ship Patent Print Art |
| 1931 ABRAHAM Submarine Salvage Apparatus Patent |
| 1931 NICK Submarine Aircraft Carrier Patent |
| 1931 ELECTRIC BOAT CO Submarine Boat Patent |
| 1931 GRIESHABER Submarine Boat Patent Print Art |
| 1931 MERRITT ROBERT Submarine Closure Patent |
| 1931 MERRITT ROBERT Submarine Device Patent |
| 1931 ELECTRIC BOAT CO Rescue Submarine Patent |
| 1931 O'ROURKE Submarine Air Lock Patent Print |
| 1931 GRIESHABER Mine Laying Submarine Patent |
| 1931 BLYTH PRATT Submarine Mine Patent Print Art |
| 1931 MERRITT Submarine Closure Patent Print Art |