[Eustace the Monk]

Since my first answer, I've added my last 2 dots to Fury. It does a great job on the hull, fair on the deck, and worthless on the sail. Very fast load/fire rate makes it a great emergency solution too. Best I can tell is this:

Lightning - Sail
Explosive - Deck
Fury - Hull

I still hate explosive though and have been loading it just to hit those miserable light sloops that like firing on me. As a solo crew member on a WG I will load up each side of the ship as follows:

Uppers - Explosive
Lower 1 - Fury
Lower 2 - Lightning
Lower 3 - Firebrand
Lower 4 - Grapple

Preloading the cannons means that you do not need to wait to switch ammo types. If running low, stand up and move over a cannon. Makes it much faster than waiting for the reload, especilly the case with Explosive.

Loot Hard!