At some point you will have to defend your ships from pirates, or perhaps "persuade" others to join your fleet. Naval combat in Patrician 3 can be a little tedious, so here are a few tips on how to do it more efficiently.
In most cases of naval battles you will need an armed ship. If your ship doesn't have weapon slots, you will need to improve it at a Shipyard or at any Repair Dock.
The Weapon Smith offers you a good selection of weapons. Catapults do more damage at larger distances, ballistae are better used at short range. Bombard and cannon are much stronger and more versatile weapons that combine the qualities of both catapults and ballistae, they are similarly effective at long range while being much more devastating up close.
When choosing the right weapons for a ship, you need to consider factors like the purpose of the ship, the likelihood of it seeing combat, as well as the cost and availability of a weapon. Cannons are harder to come by early on, so they should be reserved for your warships. Auto-trade convoys can survive with cheaper and easier to obtain weapons, since the safety of the seas is the job of your warships. Ballistae are generally more useful than catapults as a cheap weapon, since the gap between fighting ships tends to close rather fast, favouring close-range combat.
The range of weapon fire depends on the direction the ship is facing. When ship is sailing directly up or down, the cannonballs travel much farther. When the ship is facing left or right, the weapon range is greatly reduced.
Wind direction also has an impact, though there seems to be some randomness in it. Shooting against the wind will often result in shorter range.
In ship vs. ship battle, crayers usually have an advantage over other ships. Their speed and decent crew capacity allow them to outshoot and capture snaikkas, crayers and cogs. Hulks can be captured by at least cogs, or by a larger amount of smaller ships.
When equipping ships for boarding battles, don't forget to load enough cutlasses on them (as many as the crew members), since they give an advantage to the crew. Unarmed sailors can't do much in a fight.
You need to have slightly more sailors than the enemy ship to successfully board it. If you are outnumbered, shoot him until his crew drops to a more manageable level.
If you are interested in sinking the ship, keep your hits all on the same side. If you are interested in capture, spread them out to both sides.- Baltic Trader
A captain with high Sailing and Fighting skills greatly improves the performance of your ship and crew.
When attacking a town (or a pirate stronghold), your ships will have to deal with port defenses, and possibly with an outrigger fleet. You can either sink or capture the defending ships, in which case refer to the previous section. Then you'll have to destroy the cannon towers that protect the port.
Manoeuvrability of a ship is very important in a battle against towers, so Snaikkas and Cogs are better suited for this role. Towers usually aim not directly at the ship, but attempt to hit a spot where the ship is heading. You can take advantage of this, by sailing a ship in circles near the tower, and turning it slightly every time you hear the cannon fire. Remember that damaged ships lose speed and manoeuvrability, so keeping your ships safe is very important in such battles.
Patience is needed in missions of this sort. If the wind suddenly calms down, try to sail your ship out of tower's range and wait till the wind improves (it will not take long). Don't think that a smoking tower is nearly done, it can still last long enough to destroy your ship if it cannot sail. It doesn't have to sail fast, but it needs to be moving.Port Cannons are especially dangerous, and can take a surprising amount of damage.
A captain with high Sailing skill is the most appropriate, possibly with decent Fighting if you intend to board the outrigger as well.
Manual vs. Automatic Combat
When attacking or being attacked, you are given the option to steer your ship manually, or to let the computer resolve the combat.
Manual combat is a better choice early in the game. You probably control a single ship and can do a better job then AI. It is cheaper (you can do a lot of things with a single ship that the AI can't) and you can actually capture that pirate ship (that the AI is likely to sink), but it takes a lot of time.
Auto Combat is a better choice a bit later, when it's more efficient to assemble a large enough fleet and just throw it at the target. Wasting hours to clear a few pirate lairs (or town coffers) is not the best way to spend your time. You can scout the area and see what are the defenses, then send in a large number of warships and enjoy the battle report along with the loot.
Auto Combat gives the AI an advantage in that it's almost impossible to manually control more than a couple of ships in one combat. Unlike humans, the AI can actually take a huge convoy and win in a few seconds. Even if it loses a ship or two in the process (and gets the rest of them brutally damaged), the time it saves is more than worth it. When manual battles start getting tedious, build a fleet that will do it for you.
A town defended by two-three towers requires around 10-15 ships to conquer on auto combat. Multiple Port Cannons may need more. If there is an outrigger of 10-15 ships, add at least 5-10 ships to your convoy. All ships should be heavily armed (and crewed in a case of a large outrigger).