How am I supposed to investigate that area?

https://preview.redd.it/fmtvxnqh7jpe1.jpg?width=1920&format=pjpg&auto=webp&s=e5e4bacde114ce10ba70855c6d64d20cdeecda7f

I literally saw 3 of those blue leviathans and 2 electric ones. Not even counting the other annoying shark type guys all around. I could go and scan the fossil but I started taking the agro so I just paniced and escaped.

So what am I supposed to do since data base says that there is an entrance here to another biom or smting.
Try to sneak around or upgrade my robot and submarine?