Research on energy expenditure related to life and professional activity allows us to determine a person’s energy. This study determined the value of daily energy expenditure related to the implementation of service and training tasks of crews of ships in the Polish Navy and officers of the Maritime Department of the Border Guard. Materials and Methods: This study included crews of two selected ships of the Polish Navy and officers of the Maritime Branch of the Border Guard. The method of analyzing heart rate changes was used to measure energy expenditure. Results: The value of daily energy expenditure related to the implementation of tasks during a cruise amounted to 3874 kcal/d for the crew of a missile frigate, and it was higher at 4031 kcal/d for the crew of a training sailing ship. Energy expenditure related to the training of ship crews staying in a port was lower, amounting to 3648 kcal/d and 3380 kcal/d, respectively. The energy expenditure of the Maritime Border Guard officers during a 12 h shift ranged from 1830 kcal/12 h to 2762 kcal/12 h. Current nutritional standards for sailors of the Polish Navy and the Border Guard officers provide an excessively high energy intake in daily food rations, which may cause overweight and obesity.