A lightvessel, or lightship, is a ship that acts as a lighthouse. They are used in waters that are too deep or otherwise unsuitable for lighthouse construction.[1] Although some records exist of fire beacons being placed on ships in Roman times, the first modern lightship was located off the Nore sandbank at the mouth of the River Thames in London, England, by its inventor Robert Hamblin in 1734. Lightships have since been rendered obsolete by advancing lighthouse construction techniques, and by large automated navigation buoys.[1]