With Patrol you can now search for NPC fleets in a port. This new feature is expected to give a lot more strategies.
Here are some key points to consider:
A)Attacks on NPC fleets will cost your fleet +3 Danger (instead of +6 when attacking another player)
B)War fleets will most of the time not have big trouble beating NPC fleets, although Pirate Hunter fleets will not be an easy task for ANYONE.
C)Plundering can be earn a small fortune in a small time. This will get your fleets full of danger but it should not matter much in the start where you badly need gold. For later, it can still be a good option, as any good fleet who can withstand a couple of attacks (to have danger rating to 0) will be able to profit heavily from the feature.