@SesarinG.O Minimum is to be in the top 500 on your server. (Higher rank gets more rewards, look it up on the ranking page.) The required ranking points a different for each server each month, best thing would be to keep track of your servers rankings by yourself, to calculate how much is needed to secure you a spot.
I've never bothered with ranking my way up to the top, my time is limited and the rewards are not worth it for me.
@SesarinG.O: It's an advantage if it's on our ships. If the Abyssals get something similar with the ability to have BBs or something attack subs (and theirs would be ridiculously OP compared to ours), then I'll cry.
@Nanamin Well my luck counter says: If you wanna go to the Boss, you'll go to a dead end, And if you don't wanna go to the Boss, guess what~ you'll go to the Boss. :( Yeah I'm very unlucky. I know it. I don't even get the ships I want or like -_-. Scrapsy shit!!