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Submarines, Car Engines, and Displacement
On 07 Jan 2004 02:04:19 GMT, (Gould 0738) wrote:
When a sub dives to a certain depth, is that depth
measured from the bottom of the sub, the middle,
or the top. In other words, if it dives to 200 feet,
does that mean there is 200 feet of water above
it or that the bottom of it is 200 feet below the
surface?
Normally "depth to keel.
I don't know squat diddly about submarines, but I think I can answer this
question. *If* the dive indicator reads "zero" when the sub is on the surface,
the submerged depth would be measured from the normally ballasted waterline to
the surface. It wouldn't seem logical, otherwise.
You want to read depth to keel because you want it to be consistent with
the depth markings on charts. If the depth was to anywhere else, you'd
have to figure that in and it can contribute to mistakes that might
cause a grounding. I.e., if you're in an area where the min charted
depth is 250 feet, you can order a 200 foot depth safely. If it was
measured to the top and you ordered a 200 foot depth in 250 feet of
water, you'd hit the bottom.
Steve
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