Here is a British government scientific study that finds only the relatively expensive active type radar reflectors to be effective: http://www.safety-marine.co.uk/spages/how-to-choose-a-radar-reflector.htm Mike Mike Curreri GoogleVoice: 443.987.6724 Sent from my iPad3 On May 23, 2012, at 11:16 PM, "great-loop-request@lists.trawlering.com" <great-loop-request@lists.trawlering.com> wrote: > I would like to hear other's opinions about the effectiveness of adding a radar reflector. I have a 45 foot power vessel and we have begun cruising in New England waters where there are lots of foggy days. The unit I am considering is the Plastimo # 29496 ( Defender # 552203). If you want to see more details I have included a link.