where to level cannoneering

[League]

If you're a solo cannoneer, you may find it tough reaching level 12, from which point you have a good, accurate, long-distance shot. I'd just go Public until then, or let a friend take control of a ship and not fire a broadside while you shoot with the cannon (said friend would still get rep actually). This'd work best with a Frigate, as you could just man a front cannon and fire as your sailor friend just maintains his/her position: in line with the other ship.

[Poison elf]

This as other skills can also be worked together. Park your boat near a enemy ship just on radar. Use your cannon to hit the sails, soon as you hit the ship first time it will head at you. When its lined up like that you can shoot the sail mast, knocking sails down.

After you have shot off all the sails you can go to the wheel and start using broadsides until sinks. Getting rep in both sailing and cannon.

Takes some practice to shoot sails down, and you may have to jump to the wheel and pull back at first.