User blog comment:FlammeumDraco333/Tales From the Not so Blocky Seas/@comment-25373667-20150628023606/@comment-5889313-20150628143953

I suggest you use AP shells in long range engagements, usually, the deck armor is thinner, allowing you to land more critical hits.

Use HE for smaller ships and when you're at close range against a battleship.

That's what I've seen, however, AP seems to be more effective at certain occasions at close range as well.