Do you mind a suggestion here? Many moons ago when I was a CB enthusiast, I fiddled with CB antennas. Only one half of the antenna is what is stuck up in the air (unles it is a marine type antenna) the other half is the ground plane. The ground plane is what the antenna is based on, in out case generally the keel. That gives acceptable transmission parallel to the keel forward and back but minimal reception to the sides. If you were to put a wire or something metalic in the horizontal Stab(the metal framework in your horizontal stab will work) that is grounded to the keel you would also have side to side reception and transmission. Check it out, you'll get good reception fore and aft but lousy port and starboard UNLESS you have some sort of ground plane to each side.
In the early 70's we could reguarlly transmit and recieve from Near Soda Springs Ca to San Francisco Ca., a distance if several hundred miles with a standard 5 watt CB radio. We would take an alluminum boat and a battery operated Auto CB, hoist an antenna, ground the antenna to the boat, then go to the middle of the lake and transmit. Transmision and reception were phenominal.