Hello Rod,
Bailey's are usually fitted with an inboard diaphragm (positive displacement) pump. These are inherently noiser that submersible pumps for two reasons, firstly they are inboard, amd secondly they have recepiricating components which produce far more vibration, which is transmitted through the panel to which the pump is fixed.
Have word with your dealer, as there may have been a factory solution. Sometimes fefitting the pump in a slightly differnt place may help, or you can get vibration absorbing isolation pads which may help.