Abstract: The HUGIN UUV was developed for the purpose of precision mapping of the seabed. In its first version, it was equipped with a special version of the 300 kHz multi beam sonar EM 3000. The next system generation which is presently under development, will have a wider range of acoustic equipment, including the EM 2000 multi beam sonar which is operating at a center frequency of 200 kHz. The paper describes the 2 versions of the HUGIN UUV system. Particular attention is given to the mufti beam sonars which are used to map the seabed. Some examples of survey results are given.