"Terry Rago" wrote in message news:eKTKb.766800$Tr4.2203780@attbi_s03...
"Gould 0738" wrote in message
...
Fascinating. What does the depth indicator say when the sub is surfaced?
Obviously it would not be zero.

That would depend on how far it surfaced. Did it blow all ballast or is
it just barely surfaced?

Steve


It can't blow enough ballast to put the keel on the surface. My point is
merely
that if the depth is measured between the surface and the keel, (and I
have no
reason to doubt that it is) there could never be a "zero" reading.

There is never a "Zero" reading, when on the surface it
is mid to high 30's depending on the type of sub. Also
for safety sake we never surface a little bit, when we
surface all ballast is blown.

Terry

Airplane altimeters read zero only if the airplane is taxying
into the ocean. Or flying deep in Death Valley or the Dead Sea Valley.
Zero isn't necessary for operators of subs or airplanes or anything
else. I can see that depth to keel would be safest, with reference to
depth charts. In aviation we use maps with obstruction and terrain
altitudes on them.
This complete surfacing of subs: Is this due to the neutral
lateral stability at certain waterlines? I read about that somewhere,
some book that referred to the danger of submerging in really rough
seas and the danger of rollover.

Dan