wiring panel to deep cells

[SKEETR]

I'd like to isolate my starting battery for just the purpose of starting the boat. Currently have two buss's under the helm. One is wired to the back of the boat to the starting battery. Would it be feasable to abandon these supply lines and jumper to the other buss thereby running all accessories off the deep cells? How would this effect the ignition switch circuit? Does it draw power from the harness or the buss?