``Lead On!'', by Rear Admiral Dave Oliver, Jr, 1992, claims otherwise on pages 50-51: ``On the day of interest, while operating at a deep depth, the digital-readout depth gauge on this ship stuck at a few feet shallower than the desired depth. As the submarine was not quite as light as the crew thought, the ship slowly drove itself deeper and deeper. No one recognized that the two other depth gauges were slowly creeping downward, correctly indicating that the ship was going deeper.''
There's a description before this of how 44 psi is 100 feet, and some of the depth gauges showed psi and others feet, and how the standard procedure had been to have the ballast tanks trimmed light, forcing a down angle to maintain depth.
The book continues ``We made several changes in submarines as a result of this incident. For one thing, we don't trim light and run with a down bubble anymore. If the ship takes a down bubble now, except during transitory conditions when the submarine is changing depth, then something is wrong.''
There's a description before this of how 44 psi is 100 feet, and some of the depth gauges showed psi and others feet, and how the standard procedure had been to have the ballast tanks trimmed light, forcing a down angle to maintain depth.
The book continues ``We made several changes in submarines as a result of this incident. For one thing, we don't trim light and run with a down bubble anymore. If the ship takes a down bubble now, except during transitory conditions when the submarine is changing depth, then something is wrong.''