Fleets:
A ship fleet has a max of 20 ships. Normally only one fleet can be on one tile. However the diplomat can allow all friendly fleets to inhabit the same tile. Only fleets can be ordered so you must form a fleet to use your ships. You may only own 10 fleets. Un-fleeted ships are sent to the warehouse and may be inserted into a fleet at any planet you own with a shipyard. Fleets gain experience and levels as they win fights.

Speed: The speed of the ships in the fleet affects the movement rate of the fleet. The fleet has the movement rate of the slowest ship in the fleet. If all the ships in the fleet are fast ships the fleet will move much faster.