On many ships, you will find the alarms turned off (too many false
alarms) although this too is improving.
To avoid many of these false alarms, either the inner guard ring is
moved out to a range where small boats may not be detected, or sea
return is turned up to a point that close in targets can be and are lost.
Much of what is needed, is training and procedures. The Mates need to be
trained to frequently check the screen (and not just rely on alarms) but
also to scan the various ranges .... especially the lower ones.
In most cases at sea, shipboard radars will be set on either the 12 or
24mi. range, for early detection (with "sea return" minimized for best
reception) .... problem with this is that many small close in targets
can be missed.

otn

Vito wrote:
otnmbrd wrote:

Maybe someday you'll be able to rely on all ship's having at least one
radar on, but you'll never see the day when someone will be assigned to
constantly monitor it, ....


True. FWIW, the US Navy did studies that showed a skilled alert operator
could detect almost all new contacts but that one's alertness quickly
waned so that, after an hour or so detection became iffy. That's why we
spent megabucks to develop automatic detection and tracking sustems.

Also, the higher the antenna the longer the range but the poorer its
ability to "see" small craft in the sea clutter, especially close
aboard. So never, ever depend on a big ship seeing you.

73, K3DWW