Audio Systems: Stereo mute switch, lpad, mute switch

Question
I have a stereo in my boat that works well. Only one problem, when you are pulling a skier, you must increase the volume on the stereo so it can be heard over the sound of the engine. When you slow to an idle, the stereo is way too loud. How can I add a mute switch on the driver's side panel to reduce the volume? The stereo itself is located in front of the passenger, so it is not easily accessable to the driver. I would like to lower the voume, but not to completely mute it, any ideas?  

Answer
there's alot you can do here.  The easiest cheapest thing to do is put what's called an Lpad on the speaker lines,  it's a passive volume control that just give you a knob to turn the speaekrs down.  you simply put it inline with the speaker wires.
The only problem with an Lpad is that it bears the brunt of the wattage and load so there is loss and distortion.
A better but more expensive way to do it is to get an amplifier that has a remote volume control.  from the cd player you run RCA wires to the amplifier and connect the speakers to it.  this will give you better performance than you had before since the additional power from the amp will make the speakers louder and clearer.  the remote volume knob can go at your other location.
LEt me know which option you think is best for your application and I can try to help pick something out for you.