Nope,they are 2 separate systems. In a roundabout way they are connected,through grounds,but it should not hurt anything. If it did,there would be thousands of boats that are screwed up because of it.
A few battery management systems..... a battery charger converting AC to D...... like to be turned off during start up. Refer to the battery charger manual. Best wishes..
As was said, the connection from shore power to your starting batteries would be thru a battery charger or an inverter (if you have one). Neither should be affected by your starting of the motors.
My boat stays in the water 24/7, throughout the winter I often go out and start the boat. Shore power stays on because I keep heat in the boat. Never a problem.
