My limited experience with seeing passive returns was a big surprise. A
50' wooden boat broadside in calm waters 300 yards off didn't give
any return until the gain was turned up to the point it would give too
much cutter in rougher water. I also don't see too much of the folks
with the Davis type reflector, three sheets of metal put together at
right angles. The type I have is the Ferdel Bilpper, I was seen by
everyone I asked. I was able to see everyone who had a the any of the
more expensive reflectors that were covered in plastic. Apparently they
have more facets that are in more directions and give a better
reflections. I buddy boated 200 miles up the coast once with some
friends in a 46' Kelly Peterson and a 38foot sloop. The Peterson had
a Davis type reflector and the other sloop had a more modern reflector.
The sloop and I rarely saw the Kelly Peterson and were able to see each
other consistently. I was always amazed at how many boats I didn't
see on the radar. It's a Raymarine SL72
Unfortunately the active radar reflector is not cheap, about 50
percent the coast of the low end Raymarine and about $100 less then a
JRC Radar 1000 MKII. If I had a limited budget and had to choose, I
would take the radar.

John
S/V Pangea