Hi Hagar,

I use a Tri-Lens, a Lunenberg Principal device similar to SG's Lensref... It's gotten pretty high marks in comparison tests like those performed by Practical Sailor, and once looking at my own boat from another's radar, seemed to offer a very good return. Of course, it's probably the most expensive of the passive types, and also the heaviest, except for the Lensref...

In really thick visibility, I'll often hoist the Davis Echomaster in the 'catch rain' position, in addition... These appear to be 'the Best of the Rest' by a considerable margin, and offer by far the best bang for the buck... Most offshore fishing buoys you'll see off New England and the Canadian Maritimes are topped with a homemade version of this style, as is virtually every commercial fishing vessel I've seen in Atlantic Canada (although, curiously, those are not mounted in the recommended catch rain position)

If you do hoist an Echomaster, the main problem is chafe on the 'down' halyard, you really want to offset that portion enough to alleviate that...

The ones to definitely stay away from are the tubular styles from Mobri and Plastimo - they have performed very poorly in every test I've ever seen, and appear to be essentially worthless...

http://www.tri-lens.com/trilensweb12002001.htm

http://www.tri-lens.com/practical_sailor.txt

best regards,

Jon