Create a new ship using as many credits as possible. Use the "Export Ship" option after building has been completed. Return to the main menu and restart the game using a new Admiral name. Return to the fleet screen and use the "Import Ship" option to retrieve the newly created ship. Decommission the ship after it is added to the fleet to gain its value in credits. Repeat this process to accumulate an unlimited number of credits.
Star Trek: Starship Creator