Mailport: August 2014
In regard to your December 2013 Chandlery article on the Vesper SP160 VHF splitter. After too many near misses with merchant ships, we installed an AIS in 2012, using the Vesper splitter to the masthead antenna. Your article mentioned target reception at 1.5 miles without and 11 miles with the SP160. In our experience, we sometimes see merchant vessels at 80 miles or more, and other cruisers at 30 to 40 miles with the Vesper. When approaching Colon, Panama, the display was “maxed out” at 50 miles (it only shows the closest 100 contacts).
Though we have not done rigorous testing, we have traveled from Grenada to the Sea of Cortez in the past two seasons, and nearly always see merchant vessels at 30-plus miles, and the smallest sport fishing boat at 15. (I’d love to know when they see me—maybe some test could establish that.)
I thought the conclusion also left out something important: The cost of good coax cable far outweighs the cost of any antenna. If professionally installed, maybe requiring mast removal, a splitter looks more attractive.
I don’t attribute all this performance to the Vesper (though it serves us well). My point is: AIS is way better than this article suggests, and anyone making overnight transits in the vicinity of shipping should have one.
Varuna, Pearson 36 cutter
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