I've got the same unit on my boat, 4hp. The unit works fine, in all conditions, at anchor or at sea. When I got the boat, I started removing inop and outdated equipment. I identified the gyro control box mounted under the upper helm. It wasn't even connected! I saw used ones on eBay for giveaway prices, so my old gyro control unit resides in the dumpster. The "but" of the 4hp is that with some minor additional equipment, it is "capable" of HD, but the only satellite you can hit with the 4hp and only compatible receiver (D12?) doesn't have HD programming! I believe the purpose of the gyro control unit was to be able to point the antenna at a different (HD?) satellite. One last note about the D12/4hp set up is that you have to use the AV output of the D12 to the TV, not the coax. When mine dies, I'm going with the SWM capable TV5 system, but I'm inland and near coastal gulf waters.