[irishcoffee]

I actually work in this space. The difficulties of long-running underwater probes should not be discounted. Comms bandwidth without a tether is… quite slow. Dealing with even the tiniest drops of water inside the system is… a real problem. Salt water is also quite a problem. Deploy and retrieve is a real problem.

I won’t say I think outer space is easier, but the problem space is very different.

[jcgrillo]

> Salt water is also quite a problem

As a boat owner, I have had quite a time with salt water issues. Anything with an electrical current going through it exposed to salt and water is subject to serious, rapid corrosion. What you might imagine is "stainless" steel will, in fact, rust (unless correctly passivated and treated). The galvanic scale is not to be trifled with :). I can only imagine it gets exponentially worse the further below the surface you go.

[toast0]

> I won’t say I think outer space is easier, but the problem space is very different.

You didn't even mention pressure. Space is only 1 atm off of sea level. 100 meters below the surface is 10 atm more than at sea level ... all sorts of cool stuff you might want to explore is way deeper than that.

Less of a problem for robots than people, but still a problem.

[irishcoffee]

There are a lot of tricks to deal with pressure, related to filling electronic “bottles” with 1 atm of pressure via nonconductive fluid. You are correct though, pressure is also a phenomenon that has to be accounted for or you’re gonna have a bad time.

[dbish]

The comms problems are exactly what makes it interesting to me, since autonomy is fully required really.