Which of the following materials is not typically a cooking fuel on boats?

Wood chips are not typically used as a cooking fuel on boats due to several practical considerations. When it comes to marine environments, cooking fuels need to be efficient, safe, and easy to store. Unlike alcohol, CNG (Compressed Natural Gas), and LPG (Liquefied Petroleum Gas), which are commonly used because they can be easily contained, controlled, and produce a consistent heat source, wood chips present challenges such as the risk of flare-ups and the necessity for specialized equipment to manage combustion.

The use of wood chips also raises issues with space and handling, as they can take up considerable storage space and might not burn as cleanly or efficiently as the other fuels. Therefore, while wood chips might be used in some outdoor or camping settings, they are not a practical or standard choice for cooking on boats, where safety and efficiency are paramount.