Isolating tower Speakers

I currently have a set of tower speakers (Boss B-530, 1 pair). The boat has 4 kicker 6x9's in it as well. Inside it appears to be a single 1000 watt 4 channel amplifier and a seperate 1200 watt amp with 2 channels for the subs. I am trying to figure out how to be able to set my stero up so that it plays just the tower speakers at the flip of a switch or be able to control them via a remote seperately (the inside boat and tower speakers seperately). Any suggestions on how to do this?

I installed a Kenwood EQ with a fader. I use the fader to balance between the cabin speakers and tower speakers.