So a friend and I went up against the Hellfire and I got sunk, but I was close enough to the Hellfire that I was able to board it. I fought the pirates endlessly. They kept spawning and attacking me two at a time. I could not effect anything. It would be cool if I could do something to debuff the enemy ship while on board it.
#MultiPlayer Self Boarding
dusky crow
swift lava
Until you initiate the boarding process (damage the ship enough to get the boarding available icon and then bring your ship parallel to the enemy ship and press space to initiate boarding), they will respawn indefinitely if you just jump over to the other ship.