Which of the following is one of the most important safety procedures that should be adhered to prior to starting a gasoline engine on a motorboat?

Correct Answer: Option C — the bilges, cabins, etc. are thoroughly ventilated

Thoroughly ventilating bilges, engine compartments, and enclosed cabins removes dense, low-lying gasoline vapors prior to energizing electrical circuits. This critical pre-start safety protocol, emphasized in 46 CFR, prevents explosive deflagration inside enclosed spaces.