Which of the following is an essential safety item to carry on a boat?

A flare gun is an essential safety item to carry on a boat because it serves as a visual distress signal that can be seen from a distance, particularly in emergencies. If a vessel is in distress, using a flare gun can alert nearby boats or rescue services to your location, significantly increasing the chances of being found quickly and safely. Flares are especially important in situations where communication devices may fail or when visibility is limited.

In contrast, while items like a fishing rod, extra fuel, and a GPS device may enhance the boating experience or assist in navigation, they do not offer the same level of emergency signaling capability that a flare gun provides. Carrying a flare gun is critical for meeting safety regulations and ensuring that help can be summoned effectively in an emergency.