| # | Clue | Answer As Given | Value | Round | Category | Air Date | Show |
|---|---|---|---|---|---|---|---|
| In 1775 David Bushnell built the first of these underwater craft used by the military | Submarines | $100 | J | INVENTORS | 1997-02-21 | #2880 | |
| Sonar was to be used in World War I to locate these craft, but the war ended before it could be used | submarines | $400 | J | INVENTIONS | 1991-05-03 | #1550 |