The challenge of deepsea is not pressure, it’s the limited visibility and range they can get with the submarine drone. On moon and mars, everything on the horizon is visible once the sun hit the surface, but deepsea doesn’t have that perk, and water block any radiation so well the submarine need to be tethered in order to receive signal and send video feed.
Just like how we explore moon/mars, we been using remote controlled submarine for quite a while now
https://youtu.be/I1ozbgy5N-U?si=Z33ZZ0ij04uKl1le
The challenge of deepsea is not pressure, it’s the limited visibility and range they can get with the submarine drone. On moon and mars, everything on the horizon is visible once the sun hit the surface, but deepsea doesn’t have that perk, and water block any radiation so well the submarine need to be tethered in order to receive signal and send video feed.