Scuttle
This martial art is most suitable for those game worlds where every group has their own fighting style. Pirates in particular would be almost forced to develop something that could counter the inscrutable ways of the ninja; after all, the alternative would be to die in a hail of throwing stars. That’s hardly profitable!
The primary weapons of Scuttle are a cutlass in the dominant hand, and a knife in the other. Nets are also used, typically against ninja: the style encourages both dodges and trickery. Also note that a pirate with a hook hand who had been trained in Scuttle can and will use both Aggressive Parry and Hook fairly safely. These particular techniques are even taught to pirates who still have two hands, on the principle that it saves time later.