The number of maritime initiatives with hydrogen as alternative fuel is increasing. While most of the early projects aim at using compressed hydrogen the use of liquid hydrogen (LH2) is more practical and is expected to become more attractive for implementation on larger vessels due to more efficient storage, bunkering and handling of the fuel. In the industry there seems to be some confusion regarding the behavior of LH2 releases, in particular whether a release into air will behave like a dense gas or a buoyant gas. The understanding of this aspect is critical to optimize design with regard to safety. This article will explain the expected behavior of LH2 releases and discuss expected hazard distances from LH2 releases relative to gaseous hydrogen releases and LNG. Some other safety concerns of LH2, like indoor releases, releases from vent masts, potential BLEVEs and RPTs are also discussed. The article explains why a higher safety standard may be required when designing hydrogen fueled vessels than for existing LNG fueled vessels. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.