In the watery part of Super Metroid, you eventually come across a giant sea creature called 'Draygon' that you have to defeat to proceed. He's usually pretty tough to take down... unless...
All over his room are these turrets that shoot at you during the battle.
Which you can (and should) shoot with a couple of missiles to break them, which turns them into little electrical hazards.
Then, let ol' Dray pick you up and start swimming around the room (you'll get hit a couple of times, but it's worth it)
He's start swimming in wider and wider circles (as long as you don't break free) and will eventually take you within grappling range of those busted turrets. Which you should totally do.
Which will hurt a little bit, but the current mostly gets passed on to Draygon and kills him in pretty short order.
And you hardly had to do anything. It's win-win!