Abstract
A number of incidents involving offshore vessels have occurred lately as a result of lack of understanding of operational characteristics and limits for such vessels. Model tests and simulations are tools that can be used to increase knowledge of operational limits for various operations under varying environmental conditions. Presently there is however a lack of field tests that can be used for validation of models test results for different propulsors and rudder systems. This paper will give some initial results of a validation study done for an offshore vessels being used as one of the emergency response vessels operating in Norwegian waters off the coast of Northern Norway. Main focus is on zero and low speed manoeuvring performance using a tunnel thruster, retractable azimuth thruster and high efficiency rudders.