Jim, Yes. The 4" diameter wood mast will absorb the satellite signal. That signal is very weak (very low power), which is why you need a parabolic reflector in the first place. I have a tracking antenna that we've had for 16+ years; all the years we have lived aboard. When the boat swings either our wooden mast or our wooden boom through the line-of-sight of the satellite signal, we do get signal drops. I suppose this is something that an internal amplifier MIGHT be able to compensate, but it does happen. If you're swinging fairly rapidly, the buffering in our DVR compensates. But if the boat is just slowly drifting around, signal loss can be annoying. Fred Sorenson is right; a call to KVH would be worth it. Jim Peg and Jim Healy, living aboard Sanctuary http://gilwellbear.wordpress.com <http://gilwellbear.wordpress.com/> Monk 36 Hull #132 MMSI #367042570 AGLCA #3767 MTOA #3436