I use a Davis aluminum ball trype reflector mounted under one of the flybridge seats for my many foggy trips to Block I and back. I have it mounted under the seat as a result of an experiment I conducted by accident many years ago. Two boats from my marina passed me one day as I was headed to Sag Harbor. It was a sunny day but I had my radar running for practise.  One of the boats was my next door neighbor and I knew he had an Al ball mounted off one of the bows of his flybridge enclosure. The other boat was an express cruiser. I watched them on radar as they passed and both showed up as  a very large square blip on my screen. They showed the same until they turned into a harbor on  Shelter Island (Coecles avbout two miles away) when I lost them. I found out later the express cruiser had not mounted his reflector...it was under the helm seat. My deduction from this tells me it doesn't matter that much where the reflector is located other than the distance factor, but 2 miles is plenty of distance to be seen from. Jay Leonard   From: Joe hotmail <joroy40@hotmail.com> To: "great-loop@lists.trawlering.com"     <great-loop@lists.trawlering.com> Subject: GL: Radar reflectors Message-ID: <BLU0-SMTP3143569BCF198CD5CCDEA73AA030@phx.gbl> Content-Type: text/plain; charset="us-ascii" 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. I am not interested in starting a discussion on AIS at this point - just looking for thoughts on radar reflectors. This model is not expensive and seems like it should help. Thanks . Joe Cruisers 455 Currently in Great  Salt Pond - Block Island Jay Leonard leonaj99@yahoo.com --- On Wed, 5/23/12, great-loop-request@lists.trawlering.com <great-loop-request@lists.trawlering.com> wrote: