An inflatable RADAR signal device that is capable of rising above the surface of the water when deployed and that reflects RADAR emissions. The signal device is a self-contained, small, independent system that can withstand being present in a maritime environment, including being submerged in the water and/or being located on a vessel in the water, for an extended amount of time. The device includes a housing that houses one or more deflated balloons that are constructed of a material that, when inflated, rise above the level of the water and that reflect RADAR emissions. The device includes at least one gas cylinder for inflating the balloon(s), and a mechanism to trigger release of the balloon(s) from the housing including a mechanism to trigger release of the gas from the gas cylinder(s) to inflate the balloon(s).