Larry wrote:
Charlie Morgan wrote in news:d68ga2ttf187j29an5u5v5bu1b9tfblj4k@
4ax.com:


It might if the mast and the RADAR antenna looking at it were both
always perfectly aligned , but they aren't.




Therein lies the problem. Your Echomaster is atop the mast 50' in the air.
The radar antenna on the 950' containership, SeaLand "Performance" is 150'
off the water. They can see you only when you are in the beam.....way off
from the ship. When you get close to the ship, their radar shoots over the
top of your mast, completely. This is done to reduce sea return, so the
radar doesn't look "down". A target so short can't be seen very close to
the ship. Looks great on other short sailboats, though....

Think AIS....AIS....AIS.

On AIS your "return" is just as loud as the Queen Mary IIs after you get
your little transponder antenna over the radio horizon on VHF....right up
to the point where they run over you.

No problem getting your AIS beacon to set off their collision alarms....


Containership visibility directly ahead leaves a large dead zone.
A couple of years ago our Canadian Power & Sail Squadron had our Harbour
Master come in and give us a presentation on the harbour. He had films
taken from the bridge of a large container ship entering the harbour
with sailboats crossing it's path. Even from quite a distance, the
sailboats disappeared from view due to the stacking of 4 or 5 containers
high on the foredeck.