Subject: How to electronically track a net floating at Sea


How to electronically track a net floating at Sea??

Any low cost ideas to relocate a float out on the open sea using some type
of electronic device. Only need about 4 miles range.

Oceanographic gear is routinely tracked when it surfaces by means of a VHF
beacon and strobe.
http://www.novatechdesigns.com/product3.html for one

There are a lot of manufacturers

Dennis

In article i6sYa.87214$Ho3.10597@sccrnsc03,
"JET" wrote:

How to electronically track a net floating at Sea??

Any low cost ideas to relocate a float out on the open sea using some type
of electronic device. Only need about 4 miles range.



The cheapest solution is to do what the "Big Boys" do and put Radar
Reflectors along the netline every so many feet, ,and then put Radar
Transponders on both ends. The High Seas Driftment Fisherman have used
this metheod for years. If you are always within 4 miles, then you
could eliminate the Transponders and just use the reflectors, and lower
the costs considerably. You will need a good quality X-Band Radar with
at least 4 Kw Tx Power, and a good Logrythemic Receiver to make this
work.
Any "Commecial" Marine Radar with a 4ft or bigger antenna array
will fill the bill. don't get conned into any of the small, cheap,
recerational units, as they don't have the narrow Horizontal Beamwidth
antennas that are required for this type of work.

Bruce in Alaska

The USCG just busted a Chinese vessel about 400 mi W of Hawaii with illegal
drift nets. Items seized included "drift nets in excess of 10 miles each in
length and bouy transponders". Taiyo and others make them. They are pinged
by a coded HF signal and reply with a GPS position. If you are lucky maybe you
can buy the gear when it is auctioned by the govt. These transponders make the
old net buoy AM beacons obsolete. They used to operate just above the AM
broadcast band and generally below 2 MHz. ADFs were used to locate them. These
old beacons and the ADFs show up on eBay from time to time.