How do you do navigation in a submarine?

Answer 1

The primary means for navigating a submarine is via an inertial guidance system of some sort. Inertial Guidance systems use very accurate accelerometers to measure the acceleration in any direction (up/down, L/R, forward/backward), this can be derived into speeds in each direction (velocities) and further derived into actual distance traveled. Accelerometers come in different shapes and sizes such as traditional gyroscope rotors, spinning balls, lasers, and fiber optics.
Here is an example of the fiber optic variant.
http://www.ixsea.com/en/products/002.001.002.002/phins.html

As far a sonars, only active sonars accurately provide navigational data. They bounce a wave off the ocean bottom and use the doppler principle to interpolate velocities forward/backward and L/R.
Wikipedia explains this more about half way down the page.
http://en.wikipedia.org/wiki/Acoustic_Doppler_Current_Profiler

Another way to use sonar is through bottom contour navigation. Match up actual soundings with charted soundings and your speed and general course to give you a position. There is more to it, but that is the basics.

Don't forget plain old dead reckoning - use of course and speed to estimate position. This neglects the effects of set and drift, but in open ocean what's a few miles between friends.

DARPA has some new thoughts on inertial navigation as well.
http://www.darpa.mil/dso/thrust/matdev/pins.htm

The above describes navigating the sub in open ocean scenarios generally. Once surfaced and operating in more restricted waters, the submarine will use GPS and visual aids to fix their location at a given time (always in the past by the time you plot it).

Here is a ppt with some general navigation stuff.
http://www2.ku.edu/~kunrotc/academics/300/Lesson14%20Electronic%20Navigation.ppt#386,25,Slide 25

Answer 2

Submarines use a inertia guidance system. It's a complicated set of gyroscopes and sensors that detect the slightest 3-D motion of the submarine and compares it against set datum. Passive sonar is used as a dead reckoning tool to backup the primary system. GPS can be used at periscope depth. The periscope can also be used to provide visual confirmation of a navigational aid or landmark.

Answer 3

Attend the U.S. Naval Institute.

Answer 4

It was Windows Me until the upgraded to XP Pro! They tried Vista the sub kept locking up and none of the printers worked.

Answer 5

sonar...which is like underwater radar.