The simplest ideas are often the most effective. Fitting a flintlock to a cannon reduces misfires and speeds firing.
Traditionally, cannons are fired by applying a slow-burning match to the touch hole in the breach. The primer catches, flashes into the main barrel,and the resulting explosion fires the projectile. The gun captain needs to be careful, stay out of the line of the recoil, and keep his linstock away from any gunpowder. However, a burning match is not foolproof, and the method can produce misfires and, more dangerously, "hangfires" where the priming powder is burning, but has not - yet - set off the main charge.
By taking the flintlock from a standard musket and attaching it to a cannon breach, a reliable spark can be created, making firing a cannon a much more reliable process. Any risk of the slow match being extinguished, or causing an accidential explosion, is gone. The gun captain has only to cock the flintlock, stand well back, and then pull the lanyard to fire his gun. This certainty of fire is much valued aboard warships.
Historically, only the British Royal Navy and the US Continential Navy adopted the flintlock for use on cannons.
Research of Flintlock Cannons require that an Admiralty be constructed or captured.