And where are my manners again? Welcome!
Just one more thing about the course and speed estimates I mentioned.
The course estimate is one of 16 possible estimates:
N, NNE, NE, ENE and so on.
Let's say the estimate is NNE.
Because the circle is 360 degrees, and you only have 16 possible estimates*, NNE could be any course from about 11.25 degrees to 33.75 degrees.
Start the plot by drawing lines from the contact box in these 2 directions to get a wedgelike figure.
The speed estimate is a bit less informative, you only have 3* possible estimates: Slow, medium and fast, possibly a 4th very fast typically for warship taskforces.
Slow is anything more than 1 knot to about 7 or 8 knots. Say 8 to err on the side of caution.
Medium is from around 7 or 8 to less than 14, say 7 to 14 to err on the side of caution.
Fast is 14 or more knots.
Estimate how long it would take you to get inside that wedge you drew.
Use the compass to draw circles for how far the ship could possibly have traveled in the time it takes for you to get there. Make one for the minimum speed and one for the maximum speed that was estimated for the ship.
Now you have a search area. The ship can be anywhere inside that area at the time you get there, provided it didn't change its course and or speed in the meanwhile, something that can happen on occations but then it's often followed up by a new contact report for the same ship.
The hydrophone is good to up to about 20 km on a good day, less on stormy days and if you are near the surface. 40-60 meter depth is a good depth for picking up the sound at max range on just about any day.
*Convoys and task forces are different in that they will give you a pretty precice course and speed.
|