A mobile fuel monitoring system (MMU) is disclosed. The fuel monitoring system may be skid mounted and is configured to monitor fuel transfers between a fuel source and a vessel, such as a ship. The disclosed MMU is a stand-alone, self-contained unit that can be easily moved from place to place. The MMU is configured to monitor and remotely report custody transfers of fuel performed at any location. Parameters of the fuel transfer operation, such as the amount of fuel transferred, the flow rate, the fuel density, and fuel temperature can be monitored and alarms may be issued if any of the parameters are out of specification. The parameter values may be transmitted to a remote location, for example, via a satellite link.