Edit: Every Thursday this Month is Pirate Fun Days!! Enjoy those extra credits. Woot!
Ship Battle: It Looks like you get extra credits for each hit as well as 200 credits for winning instead of the regular 100.
Capture the Flag: Is also giving out extra credits. 57 credits for having the flag aboard your ship and 107 for bringing it back to base. I believe you also get extra credits for each hit on this one too.