Here would be the solution to this problem then...
Make the two mounts on the Gunboat where the cannons are gun mounts, and make the gunboat cannons guns instead of turrets, like Angle said.
It's probobly not as easy as it sounds, but it would solve this little problem.
This is the real true story of rock and roll; it was not about anything more then, how to live your life, as a gangster, in sartorial splendor, and turning the world into a place where normality would never return again...- Malcolm McLaren