system
Given the following post, respond as if you're commenting on Reddit:
human
[General] How could an aquatic species build spaceships and become a space faring civilization?
gpt
I don't think spaceships themselves are the problem. There are non-aquatic species perfectly capable of launching rockets from underwater. And while carrying water in manned rockets would add to the weight, it would also massively increase resistance to acceleration.

The real problem is fire. Not many things burn underwater. Anything that does is likely to start boiling the water unless you're deep down. And even if you are deep enough, if you heat metal to the point you can work it then it will most likely immediately start corroding in water. There are some metals that won't, but they're not going to be able to use iron or copper.

The most plausible way would be for an amphibious species that's mostly aquatic to do it. Though fire would be of little use to them, so it still seems unlikely they'd progress to metalworking.