In article ,
"Denis M" wrote:

After this summer cruise I concluded that I needed to replace my radar
reflector.

An active one will work wonders.
And (active) AIS is an even better option, provided you are aware that
only vessels over 500 tons are mandatorily fitted with one. This will
even give you the equivalent of MARPA.

HTH

Marc

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http://www.heusser.com

On Mon, 28 Sep 2009 09:39:08 +0200, Marc Heusser
d wrote:

In article ,
"Denis M" wrote:

After this summer cruise I concluded that I needed to replace my radar
reflector.

An active one will work wonders.
And (active) AIS is an even better option, provided you are aware that
only vessels over 500 tons are mandatorily fitted with one. This will
even give you the equivalent of MARPA.

HTH

Marc

Those big boats can (and do) filter out all signals from AIS-B
transponders to reduce clutter on their display. You may see them, but
they still don't see you.

wrote in message
...
On Mon, 28 Sep 2009 09:39:08 +0200, Marc Heusser
d wrote:

In article ,
"Denis M" wrote:

After this summer cruise I concluded that I needed to replace my radar
reflector.

An active one will work wonders.
And (active) AIS is an even better option, provided you are aware that
only vessels over 500 tons are mandatorily fitted with one. This will
even give you the equivalent of MARPA.

HTH

Marc

Those big boats can (and do) filter out all signals from AIS-B
transponders to reduce clutter on their display. You may see them, but
they still don't see you.

Very true, when a target is showing on the radar. I use MARPA's
information and contact the vessel with DSC. This way (hopefully) the
vessel or radar base can identify me with my MMSI number and get my GPS
position on their screen. In theory this is how it should work. I practice
it's a difference story. Most of the foreign ships have not had their
personnel trained to use DSC yet!

When practicing with friend I can track their GPS positions and they can
track me without problems.

In article ,
wrote:

Those big boats can (and do) filter out all signals from AIS-B
transponders to reduce clutter on their display. You may see them, but
they still don't see you.

If they do - they are at least at a legal disadvantage should a
collision happen.

An argument to fit an AIS-A transponder :-)

In this case an active radar reflector would be better, as it cannot be
filtered.

Marc

--
remove bye and from mercial to get valid e-mail
http://www.heusser.com

"Marc Heusser" d wrote in
message ...
In article ,
wrote:

Those big boats can (and do) filter out all signals from AIS-B
transponders to reduce clutter on their display. You may see them, but
they still don't see you.

If they do - they are at least at a legal disadvantage should a
collision happen.

An argument to fit an AIS-A transponder :-)

In this case an active radar reflector would be better, as it cannot be
filtered.

Marc

--
remove bye and from mercial to get valid e-mail
http://www.heusser.com

An active radar reflector is the way to go. The only problem is it takes
electrical power.

Power boats with a large generator have no problem.

The next best thing for a sailboat is an adequate passive radar reflector.

I am looking at the Tri Lens Radar Reflector.

It is always best to know the traffic on or close to your route.

This is best done when you are planning your route.

When this is not possible I check for traffic with the Coast Guard.

Over here we use Fundy and Halifax Traffic I visited their office and they
have the latest of equipment and land base radar antennas all around the Bay
and the gulf of Maine.

When entering narrow passages under heavy fog I prefer to make my self known
by being in radio contact with the traffic dept and the vessels in my
vicinity.

"Marc Heusser" d wrote in
message ...
In article ,
"Denis M" wrote:

After this summer cruise I concluded that I needed to replace my radar
reflector.

An active one will work wonders.
And (active) AIS is an even better option, provided you are aware that
only vessels over 500 tons are mandatorily fitted with one. This will
even give you the equivalent of MARPA.

HTH

Marc

--
remove bye and from mercial to get valid e-mail
http://www.heusser.com

AIS is on my wish list. MARPA works well and I like to talk about this on
another thread.

This summer in heavy fog I would acquire a target with MARPA. Then I would
monitor it.

At time the target speed was 5 knots going to 15 knots and back to 3 knots.
After 15 minutes of monitoring the target would disappear and reappeared
after. The conclusion was that it could have been a whale watching
pneumatic boat. I later checked with some owner of whale watching boats and
they stated very few boat can reach 15 knots. Beside that MARPA has work
wonder for me.