For Brinstar, I still haven't gotten accustomed to it yet. Though from what I can tell, one can 'camp' the right side of the stage, under the platform. You have a ledge to play with, and Aether tricksies. If you Aether on the lip just to the right of the 'logs,' you get an extended hitbox for your landing Aether, and you get a nice slide all the way back to the ledge, which naturally helps your camping game. In the same way, spacing Fsmash correctly, you can hit the pillar behind you, and then the logs in front of you, giving Fsmash a MUCH longer duration. With the platform above you and what you have in front of you to play with, you have A LOT of options covered.
This is all theory-craft...coming from very little experience, but now this is sounding fun...I'll have to practice up a little more. I should consider this counterpick more often...I find myself counterpick Battlefield for everything these days.
As for Pirate ship, of course there's water for water spiking, but the biggest advantage we have here is that we cannot get gimped. At least no more than any character can in water.