Getting time for new batteries on my boat. My boat is rigged with two batteries for cranking/accessories on a "Off-1-All-2" Perko switch. It's had two starting batteries on it since I've had the boat, and I'm thinking I may be better off getting one starting battery and one deep cycle battery. I'm not sure though. They stay on an onboard trickle charger 24/7 when not in use.

These two batteries serve the following purposes:
-Cranking a 225 Optimax Pro XS
-Bobs Jackplate
-Tilt/trim
-One Powerpole
-Three Garmin echoMaps
-Nav lights

Would I be better off having a dedicated starting battery to crank the motor/jackplate/tilt and trim, while in conjunction having a deep cycle battery dedicated to the three Garmin's and the Powerpole? Or, just continue running the two starting battery setup.

I'm a big fan of two separate batteries with the Blue Seas ACR add a battery switch. It has All On, All Off, and then Emergency Combine.

Additionally your motor will charge both batteries while running.

So now you have a battery dedicated to starting. A separate isolated battery dedicated to accessories.
You turn them both on/off with one switch. AND it's a failsafe like having jumper cables hooked up all the time. If motor won't start and you are in a bad spot you can hit it to emergency combine for that immediate jumper.

Seamless....no brainer. It's all on/off....charges both....and gives you emergency backup all from the switch.