Which organization regulates the transportation of explosives by water?

The correct answer is the United States Coast Guard (USCG), as it specifically oversees the regulation of transportation of explosives by water to ensure safety and security in maritime operations. The USCG enforces a range of maritime regulations that include the shipment of hazardous materials, which encompasses explosives. Their regulations govern not only how these materials are packaged and labeled but also the training required for personnel handling these shipments, as well as protocols to adhere to during transport to prevent accidents and ensure safe passage.

While the Department of Transportation (DOT) does play a broader role in regulating the transportation of hazardous materials across all transportation modes, including roads and railways, the USCG is the agency specifically tasked with maritime regulations, making it the authority for water transportation of explosives. The Environmental Protection Agency (EPA) and the Federal Aviation Administration (FAA) do not regulate maritime transport of explosives, as their focuses are on environmental protection and aviation safety, respectively.