[PUP] Med Bound 2007 Noon Report - June 22: Of fish and fish

[Dave Cooper]

<Milt wrote:.....AIS....Here's data for the
first two ships....>

We have been getting far better range on the ships we encounter here in the
Caribbean since we changed to a COMAR CSB200 Class B transponder. Very often
more than 40 miles and most often in the 32-35 mile range. These are the
tankers and cargo ships generally either Panama bound or heading from Panama
across the Atlantic. The tankers are usually bound for Trinidad and/or
Venezuela. Cruise ships are also in this mid 30's range

A few of the smaller mega yachts are typically in the 20 mile range.

I think what this is showing is the effect of antenna height on the signal
but there must be other factors here. A difference in say 50' on a cargo
ship vs. a mega yacht wouldn't account for a 15 mile difference.

Our SR161 from Milltech was giving just shorter ranges on an average. So if
Milt and the others are getting such significant shorter range I would
certainly look at both the units themselves first and then the
installations.

We of course still have the issue that most Class A unit can't see our name,
course or speed. They all see out MMSI # and our lat/lon and that's it. This
is a known software issue on the class A units as the class B units had not
be finalized when the requirement for class a units were made mandatory.
They forgot to make any requirement that they be upgraded on any kind of a
schedule so the class B units are basically "dark" right now to the majority
of shipping :-(

Dave & Nancy
Swan Song
Roughwater 58
Caribbean Cruise '07