Water planet? How does one break into underwater exploration?

[Pronoun Paladin ☯]

I've seen videos of underwater exploration, I've seen the base building options, but how does one break into switching from space to underwater. My ship doesn't seem to want to go underwater -found a planet that was almost entirely water and the water appeared to be fairly deep. Do I need a special starship? Or perhaps something unlocked via the storyline.

[Captain Brendig]

Nautilon sub. Dreams of the Deep or something. Barely got into it when it first came out.

[Mr. Bufferlow]

You will need to find some area of ground to land on. If you head back to space and get a bit away from the planet, you can often make out where there is land.

At least in my experience, never seen a planet with 100% water. There is usually one area that is almost exclusively water and another area where there are more lakes or at least a large group of islands.

You can either go with the sub or upgrade to 3 S class underwater protections- or both. I find the sub to be a pain to summon, use, and refill...so normally just rely on the underwater protections.

You can also get the water jets addon which makes it pretty fun to cruise around underwater.

Anyway you slice it, it is pretty interesting exploring.

[BigGrayGolem]

Spaceships don't go underwater. Eventually the storyline will have you build the submarine. Even then you will have a hard time finding planets with deep oceans, they are more like shallow lakes. But they do exist.

[Däguas]

As cbkohoh said, Dreams Of The Deep. It's a secondary mission that's unlocked in the Artemis mission after The First Traveller is finished.

[Tesityr]

If I may add to the already helpful information here, you *might* be sent to a Water Planet 'automagically' by following the Underwater Questline (Dreams Of The Deep, as mentioned by other knowledgeable people here) - I was.
I had never SEEN an almost-all-water planet until I did the Questline (after finishing the game once and exploring to many planets/systems).

Be warned, that it might take a long time of flying around on the Water Planet to find some land to set down your spaceship:
https://steamcommunity.com/sharedfiles/filedetails/?id=1766817780
Tip:
After finding some land to set down and after beginning your Underwater Adventures - if you ever want some Land to call your Ship to - find some land that rises up close to the surface [while underwater], then just ADD to that Land with your Terrain Manipulator to create enough 'area' above the level of the water, to call your Ship to.
(This will be better understood when actually going through this Quest)
This way, you can access the Ships' Inventory, fly away to another planet for a break, or just have some land area to build on, etc.etc.

Lastly, the underwater locations might be kilometers apart, as in 10-15 minutes each. After the first 1-2, getting over the novelty and how neat things looked, it became a bit tedious.... (Not sure why my Locations were so far apart... RNG Gods Unhappy that day lol) Try not to let it get to you, heh.

Good Journey, Traveller

[Asmosis]

oh i never travelled long distance in the sub, i always went back to my ship and found an island close to the destination.

Perhaps i should have, since now im constantly out hunting for those green things off the geothermal vents.