Ensure that all people onboard have own life jacket.

Sea condition is sufficient for your boat.

Dead man´s switch is switched to driver. 

Ensure that you have fire extinguisher(s) onboard and they are not expired.

Ensure that you have needed ropes and anchor onboard.

Check that there is no water on bilge.

Check that all bilge pumps work.

Check that there are no fuel or oil leaks, bilge.

Check that deck drain system is clean and valves are open.

Check that all deck hatches are closed tightly.

Every fuse is in lower position.

Main switches are switched on.

Batteries have enough power.

Engine works properly.

Engine cooling water flow.

You have enough fuel onboard.