[mookiemookie]

If you're using deck guns, make sure that you aim your shots at various points along the waterline or just below so that it floods. Punching a bunch of holes in the side of a ship above water isn't going to do much to sink it.

That being said, I believe the damage model in stock is based around a hitpoints system, so you may theoretically be able to sink the ship that way. I dunno.

I do remember one time I sank a freighter with one shot. I think I hit the engine room or fuel bunkers, because it went up like 4th of July fireworks.

And you're right - once they start shooting back, it's time to ditch the deck gun altogether.