Yes, that is their salary but that isn't their total "cost". From the navy's budget perspective people cost much more than their actual salary (benefits, admin cost etc).

Example. I work in the military. I am paid a salary. But, as a government employee I must take certain online courses (anti-bullying, sexual harassment, workplace safety). These are from another department but are budgeted as if they are from an outside organization. When I take the class, at no cost to me, the fee for that class moves from one pile of money (my unit's training budget) to another (the unit offering the course). Such expenses, even though internal to the larger organization, are budgeted by individual units. They are a cost associated with my employment but are not salary, tax, benefits or anything else employees might see on their paychecks. Such costs are real and must be anticipated whenever you hire people.