Broadsides now implemented

In 0.7.8 you can now fire a broadside either port or starboard using the buttons on the cannon tab in the bottom left.  When you fire a broadside you do not need to be looking down the sights of the cannons on that side of the ship.  You can even be in 3rd person camera mode when doing so. 

How this works is you have to go to Battle Sails.  After 6 seconds at Battle Sails the broadside activation buttons become available.  When you fire a broadside all cannons are fired parallel to the sea, straight left or straight right from the ship.  If you are aiming the cannons, your aim is ignored.  You cannot manually fire cannons on that side of the ship until the broadside has completed. 

Cannons are fired in highly rapid succession, much faster than manual fire.  If your ship has multiple gun decks on each side, ALL GUN DECKS ARE FIRED AT THE SAME TIME.  The ships with 3 gun decks on each side get the most benefit from this.  Even on the largest ships, all guns are typically fired in around 1.5 seconds.  Ships with fewer guns even faster. 

The biggest negative is since you cannot aim guns up/down, ships with guns mounted high above the water may shoot over small ships.  In that case you should continue firing cannons manually instead of using a broadside.  Firing a broadside is most effective against larger ships.  Large Frigates vs large Frigates, or between Ships of the Line.