We stopped suddenly last year when the initial petrol tank was emptied. Its quite strange when you go from a noisy motor to complete quietness and are just floating and bobbing about on the sea. It's always a relief when the priming from the reserve tank works and the motor restarts.
If nobody, on the trip, has used one of these boats before, it's well worth taking extra time to listen to all of the instructions, especially about how to use the reserve fuel tank. Make sure your mobile phone is charged and in a plastic bag along with any cameras, and take plenty of water with you.