On Tue, 6 Jan 2004 19:24:30 -0500, "Gary Warner"
wrote:
I've had a few random questions rattling around the
brain for a while - figured I'd pose them there.

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?

Interesting question but I have no idea.

On modern gas car engines and when it's cold
outside, is it still better to let them warm up a
bit and how warm (how long) is necessary?

Not necessary at all assuming everthing is in tune and the engine is
running smoothly. Just don't over rev the engine until it's up to
operating temperature, usually within a few miles.

Anyone have a good way to find the total surface
area of my boat hull while it's in the water? It's
a 22' boat, not very deep V, "square" transom. I
did some estimating, but wonder if there are any
creative ways to get more accurate.

If you piece it out into a rectangle and a triangle on each side, you
can get pretty close with a deep V hull. Given the deadrise angle and
length we could develop a trig formula that would be a good
approximation, but it's easier to piece it out, and you'll have a
better intuitive sense of the answer. (Length x Beam) + a small fudge
factor will also get you pretty close.

"Wayne.B" wrote in message
...
On Tue, 6 Jan 2004 19:24:30 -0500, "Gary Warner"
wrote:
I've had a few random questions rattling around the
brain for a while - figured I'd pose them there.

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?

Interesting question but I have no idea.

On modern gas car engines and when it's cold
outside, is it still better to let them warm up a
bit and how warm (how long) is necessary?

Not necessary at all assuming everthing is in tune and the engine is
running smoothly. Just don't over rev the engine until it's up to
operating temperature, usually within a few miles.

Anyone have a good way to find the total surface
area of my boat hull while it's in the water? It's
a 22' boat, not very deep V, "square" transom. I
did some estimating, but wonder if there are any
creative ways to get more accurate.

If you piece it out into a rectangle and a triangle on each side, you
can get pretty close with a deep V hull. Given the deadrise angle and
length we could develop a trig formula that would be a good
approximation, but it's easier to piece it out, and you'll have a
better intuitive sense of the answer. (Length x Beam) + a small fudge
factor will also get you pretty close.

When the boat is in the water, draw a line on the side a short distance
above the water line, say 1 inch, with a grease pencil or sharpie
marker. Then when the boat is out, use a 1 foot square of cardboard and
trace around it to make a grid from the keel to the waterline. Only
have to do half the boat, and so only will have maybe 50 or 60 squares.
you could make smaller rectangles or triangles to fill in gaps if you
are going for ultimate accuracy.

Suggestion 2. Instead of the squares, cut black plastic and tape to
exactly cover wetted surface. Weigh on accurate scale. Weigh a known
area. divide.

del cecchi

"del cecchi" wrote

Ahhh yes, there are the creative ideas I was thinking
must be out there.

Thanks to everyone that responded to these questions.