[CA] [CA11] Separate circuit for electronics

[tonyiiiafl]

I am thinking of running a separate circuit to the fly bridge of my 1994 CPMY for the electronics. I would make a run from the back of the main battery selector switch which is under the stairs, up the wire chase and under the dash panel. Overall length of approx. 15' I would place a battery disconnect switch up there so I could effectively shut off all electrical from the electronics while they are not used, and also more effectively isolating the electronics further from the main house system. I know from the fuse sizes there is not a heavy load or draw.

I have:

9" RAY e97
12" Ray e127
Quantum 2 Dome
Raystar 130 GPS
Evolution Auto Pilot

What sized cable would you suggest? Would a number 4 be sufficient? Or should I go to a #2?

Thanks!