Naval units are constructed at shipyards or in factories. Individual ships can be purchased on the open market or stolen. Navies are just organizational units that can be assigned commanders depending on the size of the force. Subgroups can be formed for specific operations, however the subgroups will still operate with the rest of the fleet unless given other orders.
Navies need credits, refined materials, gas, food and people to operate. They can be used to battle other fleets, defend, escort, interdict blockade, patrol or intimidate or to board other vessels or patrol shipping lanes. Lack of credits lowers morale and increases failure rates. Refined materials are needed for repairs. Crew is needed for piloting the ships and (in case of absence of ground troops on the ship) for boarding parties. Lack of food will cause attrition in the crews. Gas is needed to power reactors, engines and lasers. Crew can escape using escape pods. After battles prisoners and salvage can be collected (or destroyed). Any captured vessels are able to be reverse-engineered (such that the faction is able to build it) or put to use (or both, but not at the same time).
