I actually noticed this a while ago and never really got around to investigating it, but… how do you turn full power OFF? I was exploring the south and got attacked by a jillyfish outside Port Carnelian. Went full power to zip into port, did all my stuff there and left again. No indication of whether full power’s still on or not, then a few seconds later my engines blew up. I figured that at least that would cancel it, but even afterwards I was going much faster than normal, taking my speed down just meant I was going faster than normal at different speeds including backwards (I couldn’t tell if I was moving at 0 speed since there was no nearby land by then but from the water movement it sort of seemed like I was), and pressing F again just gives you the message that you’re turning on full power every time.
Surely a) docking and b) lowering your speed should both turn it off, and there should also be a message saying when it’s turned off. And pressing F when it’s already on should say "you’re already going at full power" or something, so there’s a way to tell whether it’s still on or not.
I think that’s the only problem I’ve had since starting this new game on release day though. Everything looks utterly stunning and I’ve found new stories in places that were placeholders for a long, long time. (Nuncio! Nuncio is excellent.)
Full power is a finicky bitch as they should be. Full power will raise the temperature of your engine [indicated to the left of your fuel meter in the upper left of the screen]. So. Pay attention to your engine temperature [normal is 200 degrees] to know when you are still utilizing full power. If your engine is above 200 degrees at all it has the chance for all the bad things to happen
Edit: You have to mouse over the temperature gauge to get a pop up of the actual temperature edited by GerbilSchooler on 2/10/2015
Your engine temperature slowly lowers after hitting Full Power; you’re probably still at risk until it stabilizes. There doesn’t appear to be any way to speed up that process, you just have to wait for it to cool down and hope you don’t blow up in the meantime. Don’t hit F again, or click the temperature gauge, though - that’ll set it back up to full power, extending the time.