I was told they work just as well in a box under the seat on the fly bridge.
I can verify this is true at least up to a couple of miles.
A few years ago a pair of boats from my marina passed me on their way to a destination in the same direction. As they passed I noticed the nice square radar blip they both had. I commented on that via VHF . One boat was my marina neighbor and he had the Davis reflector mounted high inside his flybridge enclosure.
The other boat was an express cruiser and I asked Leo where he ended up mounting his because the images were the same.
He responded it was still under the helm seat.
I followed their blips for several miles and as they turned into an anchorage almost out of sight the blips were still identical.
-- Edited by jleonard on Monday 25th of October 2010 04:58:15 PM