The cosmos are amazing. Every day we get images from Hubble or Keck, and each image is more spectacular than the last. Contrast that with the ocean floor which is, and I use the oceanographer’s term for it here, a class-A shithole. That is why space is so much better than the ocean.
According to my research, we humans have only mapped about 10% of the ocean floor, which covers 70% of our Earth. Contrast that with the surface of Mars, of which we have mapped 35%. This is so even though Mars is a years-long spaceflight away.
Hell, many of us are in danger of falling into the stupid ocean if we don’t watch where we’re going on the way to work. Mars is in space, though, and therefore beautiful. The ocean floor is covered in gross mud. You suck, ocean!
It’s kind of like the difference between archaeology, which uses hard manual labor to make discoveries about past cultures, and digging into the piles of crap in one’s own garage, which uses manual labor to ruin a Saturday.
Mind you, space or the ocean, either one, will happily kill a person, but at least in space you will very likely have something nice to look at before you asphyxiate. You have only to descend a little bit into the ocean before you can’t see a damned thing.
Also, space is helpfully free–so far, at least–of spooky creatures, whereas the ocean is chock full of them. Even the ocean’s surface animals are weird as hell.
All I’m saying is, there’s a reason why we have the technology to map the entire ocean floor and we haven’t yet: it is dumb. Give me space exploration every time.