steve, no one talking here about the radar on military ships. we are talking
about the radar on recreational sailboats. go back to sleep.

then how come you are such a dumb squat when it comes to radar?

I probably spend more time as
radar observer, on my week off, than you do in a year.

indeed, you didn't even know you need nearly flat water to see low rocks
with
radar, as witness your statement below:

That may have been true in the 40's and 50's. It's not true anymore.
There are all sorts of techniques modern radars use to find things like
low rocks in sea clutter, from simple ones like scan averaging and
doppler filtering to complex adaptive filters which model the sea
clutter and remove it.

Steve