Today there is a need to measure the abilities required to be successful as a combat boat driver before the start of duty. The aim is to avoid unnecessary drop outs during the training, which will both save resources and increase safety during training. The purpose of this study was to validate the test that is currently used for selection and develop new tests that measure the abilities required to be a successful combat boat driver. The study started with a cognitive task analysis with the purpose of elicitating those abilities. Observations and interviews of the privates and the instructors were made, and a test battery was constructed. The test battery measured spatial and verbal short term memory, problem solving ability, the tendency of risk and social ability. The results from these tests were compared with instructor stings of the privates performance during training. The study showed that the current test can not predict the abilities that the instructors think is important to be a successful combat boat driver. The only test that predicted a successful combat boat driver was the test that measured verbal working memory.