No list, nevertheless, for me desiring departure:
Check weather forecast and decide if boating plan needs to be canceled or modified.
Bring aboard and secure desired supplies.
Wash down boat if needed.
Hoist any desired flags.
Flip all switches at the electrical panel for desired systems. Check if systems are operating.
Check any notes left concerning thru-hulls or other matters of concern to be opened or addressed.
Check fuel levels of tanks. Assure adequate fuel supply, particularly the one currently connected. Same for water tanks.
Having previously noting any boat lean, switch fuel tanks when needed.
Disconnect and bring aboard shore electrical line.
Start engine. If no instant start, fuel-prime.
Once engine started, check adequacy of exhaust water flow and engine-gauge readings.
Disconnect and secure dock lines.
Change gears only at minimum RPM, orient boat with bow thruster or other means so exit from berth is "clean."
Check operation of air horn: three shorts backing from berth and/or one prolonged exiting marina.
Bring aboard fenders after leaving berth.