Final answer:
A good safety precaution when fueling a boat includes sniffing for fumes afterward, ensuring good ventilation by running the ventilation system for four minutes before starting the engine, and keeping all openings clear to disperse vapors.
Step-by-step explanation:
A good safety precaution when fueling your boat is to sniff for fumes after fueling and before you start the engine. It is also essential to avoid creating any potential sources of sparks or flames during the fueling process. Ensuring good ventilation should be a priority; therefore, you should run the boat's ventilation system for at least four minutes before starting the engine after fueling, and keep all windows and doors open to disperse any harmful vapors. Moreover, similar precautions should be taken when handling any chemicals or gases to ensure safety, as outlined in guidelines for laboratory safety and scuba diving practices