| Year | 1956 |
| Date | 26-Jul |
| Volume | 115 |
| Issue | 2,879 |
| Page | 124 |
| Category | Nautical |
| Part | |
| Title | Modern Navigational Aids. The Echo Sounder |
| Author | A Cecil Hampshire |
| Notes | The Subsig type No. 101 recorder, Kelvin Hughes Kingfisher echo sounder, tremendous amplification, Kelvin Hughes Fishmaster, sound beamed downwards |