In which scenario should boaters avoid completely filling the gas tank?

Boaters should avoid completely filling the gas tank to allow room for expansion. Gasoline can expand and contract in response to temperature changes. If a gas tank is completely full, there may not be enough space for the gasoline to expand when it heats up, which can lead to overflow and potential hazards, such as fuel spills or fire risks.

Understanding the behavior of gasoline in varying temperatures is essential for safe boating practices. For example, if a boat is refueled in cooler temperatures and then encounters warmer conditions, a full tank could lead to an unsafe situation. Therefore, leaving some space in the tank is a precautionary measure to account for these changes in fuel volume due to temperature fluctuations.