The secret is moving sideways. Despite the pretense being that you're stranded in an alien environment that's fundamentally hostile to human life your character is perhaps the single most maneuverable and agile creature in the ocean. Leviathans are another story, but they're a (mostly) static threat to work around, and even there you can trivially take them down once you get a stasis rifle or torpedoes.
That said yes, it's a terrifying game that both keeps you functionally tethered to whatever your current lifeline is (whether that's a submarine, mech suit, or literally a breathing tube going up to the surface) and is constantly forcing you to stretch the bounds of where your comfortable being.
My only real complaint is (vague endgame spoilers)
Once you get the sub fully upgraded, which is basically necessary to enter the endgame areas, you no longer have any real reason to build a base. Like there's no incentive to build anything down in the river or [REDACTED] zone, which is a shame because those places are fucking beautiful and I'd have loved to have an excuse to set up a sustainable base in a scenic spot down there to facilitate something that the sub can't provide.
I could never find a way to bring my sub down into the really deep places, which meant that I used the mech suit and built a serious survival base down there, and until I had that base really built up, I was ferrying things back and forth through that entire area from my sub. I probably made 15-20 total two-way trips.
spoiler
IIRC the mats for the biggest depth module were in the inactive lava zone. I built a little base by the tree as a staging ground before heading deeper, but got the mats I needed on the first voyage and only stopped back in a few more times when passing by, mostly because I also set up a little farm there and also because it was just so beautiful there, hanging over a dark void surrounded by all the glowing plants and fish.
spoiler
yeah it wasnt the depth i had issues with, it was literally fitting my submarine down there. my entrance to that entire subterranean area was too narrow for the sub. but yeah, i also made my base near the tree, i never really felt the need to build any deeper than that. excursions staged from there seemed to do just fine.
spoiler
There is an entrance large enough for the sub in the north between the bulb zone and mountains.
spoiler
IIRC there are three entrances to the river and two are large enough to get the sub through, though one of those is a tight fit.
You can do it. I'm also afraid of the ocean, but I managed to complete the entire game. It's fucking terrifying in certain places. There was a point in the game where I was staring into a black pit in the ocean floor and my AI companion basically asked me, "Are you absolutely sure you have a good reason to be here? There are giant monsters here." And for the first time in my entire life, I did not take that as a challenge. I agreed with the AI, no I did not have a reason to be where I was. I turned around, and I went home. I do not regret it.
I'll absolutely never forget that moment.
You should go for it! The game is also super fun in VR. I got a change to try it on a Vive at a friends house and it was unreal.
There's a multiplayer mod for it, but it's pretty jank
Play Breathedge. Tremble in terror at the cold vastness of space instead :D
Play Aquanauts Holiday for the ps1, you just explore da seas, talk to fishes and build a coral reef.
It's a very early ps1 game so there's not a boat load of content, but it is relaxing to just glide around looking at the low poly aquatic life.
Holy shit I'm not the only one. Big fish scared the shit out of me on my first game and I had to stop.
if they made this game in vr and made vr cheap i think that would be a cool experience
https://www.youtube.com/watch?v=-NBMdcUTC2M
VR can be cheap. You don't need there best of the best from what I understand.
yeah i dunno, after watching that i'm feeling like vr just isn't where it should be for me to get enjoyment out of it quite yet. basically having to wear headphones and hold controllers sounds horrible. if it were gloves and the audio was built in and the view went beyond your bounds on an affordable system they might have something, but until then that seems like a nightmare
Conquer your fear. Also you later get a stasis rifle which is pretty useful