1.   A depth gauge is essential for telling you how deep you are when diving.

2.   The reservoir depth gauges, at any instant, would tell the engineer how much water is in the system and where it is.

3.   Besides, as one Hampton sailor says, look at the depth gauge.

4.   But it does, and slowly, very slowly, the digital depth gauge registers an upward movement in the sub.

5.   For a couple more bucks, why not throw in a tire-tread depth gauge?

6.   Impossible, I retorted, explaining that I had looked at the depth gauge several times.

7.   The depth gauge wavers for a few seconds, then starts upward, faster and faster like an express elevator.

8.   Use a penny as a tread depth gauge.