How many Fierstein wisher's or required on board and 18 foot powerboat with installed fuel tank?

For an 18-foot powerboat with an installed fuel tank, at least one fire extinguisher is typically required on board, according to U.S. Coast Guard regulations. However, if the boat is equipped with a built-in fuel tank, a Type B fire extinguisher is usually mandatory. It's important to check local regulations, as requirements may vary by state or region. Always ensure that the fire extinguisher is readily accessible and in good working condition.