AP/HE Shells

How do I know if my target is armoured or not?

Test it out. Testing is the primary method of discovering if a ship has armour or not.*

Fire a salvo at your target and follow it up by the other type of shells on your next salvo. 

You need to pay attention to the numbers that pop up over the enemy ship when you score a hit. If they are big white (deck), big green (belt) or big yellow (crit) hit then the shell is doing it's work.

If the digits coming up are small and grey coloured then the shell type you are using is less effective. Either because you fire HE against armour, or AP shells against no armour. Both resulting in a poor hit.

Once you determine if the target is armoured or not, switch to the corresponding shells to inflict maximum damage.

Usually a couple of broadside salvos will eat up any ship armour. If you are taking damage as well get those AP salvoes on target and switch back to HE after the armour is away.

* By knowing what speed your target ship goes when upgraded, see whether it is travelling faster or slower than the known value. It's still a guess if he actually has armour or not. But it's a safe bet that he has armour on board and that's what's slowing him down a few knots.

How much AP shells should I select?

In general it's always a good idea to be packing some AP shells. Usually you will want somewhere between 10% - 20% AP to give you enough throughout the whole battle.

In situations where there are lots of high tier battleships, heavy cruisers and even destroyers, you might lean more toward 20% AP.

You will have to gauge as well as you can if players equip armour. In general most of them do. (unless they travel very fast, in which case they probably are using a speed set up)