                               Command : SONAR

NAME
   sonar - Use sonar to look for ships

Level: Basic

SYNTAX
   [##:##] Command : sonar <SHIP/FLEET> <brief?>

The  sonar  command allows ships to look for submarines and submarines to look
for ships.

If the <brief?> argument is specified then the sonar map will  not  be  drawn.
This  is  useful  if  you  just  need to see the list of ships you can detect.
Whether or not a map is printed, the sonar information will be added  to  your
bmap.

Only ships at sea may use sonar and sonar only detects ships which are at sea.
Furthermore, there must be a straight line of water between the  detector  and
the detected (sonar doesn't work around corners).

In the current implementation, sonar works similar to lookout.  The major dif-
ference is that a submarines cannot use lookout  to  sight  ships.   Likewise,
submarines cannot be sighted by ships via lookout.

There are two aspects to sonar - passive and active sonar.

ACTIVE SONAR

This  is the most visible form of sonar.  It is simply a ship's ability to use
sonar pings to detect other ships.  The range of  a  ship's  active  sonar  is
identical  to the range that it can sight ships via lookout.  (see "info look-
out") When you type "sonar 25", you are using active sonar.

PASSIVE SONAR

This is more subtle.  Passive sonar is a ship's ability to hear sounds, mainly
active  sonar  pings.  When a ship pings you with active sonar, you can detect
that ping.  If a ship with sonar gets pinged, that country receives a telegram
saying   "Sonar   ping   from  x,y  detected  by  ship  Z!"   In  its  current
implementation, passive sonar is the ability to detect a ping.

When a ship emits a ping, that ping has  to  travel  out  to  a  target  ship,
reflect  off  of  it, and then return to its source.  So, in order to detect a
ship X sectors away, a sonar ping must be able to travel 2X sectors - from the
source  to  the  target, and back to the source.  So, if a ship can use active
sonar to detect ships X sectors away, passive sonar can detect  active  sonars
from  2X  sectors  away.   So the range at which you can detect sonar pings is
twice the range at which you can use sonar.

The active and passive sonar modes means that you want to be careful when  you
use sonar, because you will tell others where you are long before you actually
detect them.  This also gives you some warning before you get  your  submarine
attacked,  as enemy ships have to use sonar to find you.  The key to submarine
warfare is "run silent", meaning use your sonar only when you have to.

On the other hand, destroyers are designed to hunt subs.  A destroyer guarding
a player's coast should use sonar often, especially if it has other destroyers
nearby to support him if he gets in trouble.

For example:
   [##:##] Command : sonar 3

   sb2 submarine 2 (#3) at 24,0 efficiency 76%, max range 2
   Sonar detects TheBorg (#5) bb4 battleship 4 (#1) @ 23,-1
     .
    . B ?
   . . 0 ?
    . . .
     . . .

Sonar-capable ships of tech 310 or better can also  detect  mines  with  their
sonar,  although at only half their normal sonar range.  Mines will show up on
the sonar map as 'X' and this 'X' will be added to your bmap.

In the case of using sonar to detect subs, detection = (sub visibility +  ship
spy  value).   If detection is less than 8, then the sonar will just print you
something like:

     Sonar detects sub #12

If detection is above 7, then you will be told the ship type,  and  if  it  is
above 9, you will also be told the owner of the sub.  Note that type and owner
will always be shown for Friendly subs.

Planes with the ASW ability can use sonar while on recon  missions.  See  info
recon for more details.

SEE ALSO
   coastwatch, Ship-types, Sector-types, radar, recon, Ships, Detection

