Water physics help

Okay, so, scene setting: I am making a space station, in this space station, is an island get away. Weird, I know, but also non negotiable.

Now, in this space station island get away, I plan to have a beach, a ship, a fake ocean for which the boat to sit in and the beach to sit next to, and most importantly for this thread: a secret pirate bar under the beach, accessable through the water.

So to clarify, I want the entrance to an underground location be accessable through an artificial body of water I will place after the fact, a tunnel which players will have to walk/swim through to come out in the underground pirate trove/bar.

The issue is, this bar is well beneath the intended water level, and, while logic and game mechanics in the hylotl dungeon says that is possible, in reality, no matter what I do, the water tries to flow up the tunnel.

I would simply use a drain, except I do not reeeaaally want to be constantly having to refill the pool with water, and there is no way to have constantly spawning water outside of an ocean planet.

One solution I have tried is to make a pair of doors that could act as a pressure lock, only having one open at a time.

The issue with this is for some unholy reason, doors seem to retain water, and every time the system is used, it pumps more water up/across the tube, not a huge amount if you wait for it to restabilize (There IS a large initial influx, but that goes down if you wait a few moments), but enough to make the system certainly not ideal.

Another solution of making the path needlessly complex and winding slowed the influx of water, but by no means stopped it.

SO TL;DR:

IS THERE ANY WAY TO MAKE AN AIR POCKET THAT DOES NOT HEMORRAGE WATER

 

NEVERMIND I FOUND A MAGNIFICENT SOLUTION AND IT USES COCONUTS

 

I've been testing stuff in an ocean biome (for easy access to more water)

While seperated doors didn't work, and allowed the camber I am standing in to be (slowly) flooded, and while drains would eventually cause the resevoir of water to fall to the level of the drain, creating a seal of coconut milk, swamp water or oil ALL successfully stops the water from rising any further.

I am posting this so that if anyone ever has the amount of confusion or frustration trying to do exactly what I just did, can maybe find this post and have all their troubles be over.

Things to keep in mind:

1: To do it, I placed blocks (5 wide to match the width of my MM) to act as a stopper just below where I wanted the water to stop, then blacked a block to hold in the coconut from spilling into my chamber, then when the coconut milk was even I used the matter manipulator to destroy the stopper blocks all at once, causing the milk to drop evenly down one block, creating a perfect seal, removing the one block used to hold the coconut milk, the level evens out to match the height of the pillar almost perfectly (would have been perfect, but I used 4 milk instead of 5 hahah--)

2: You can have an even finer layer of milk/oil/swamp water, but it will result in it not meeting the block layer. If you make it too thin however, the game physics get a little screwy and it can not work as intended.

3: This will not work if you substitute the seal liquid with poison or healing water, as they will just mix with the given water type, however, the seal does appear to work to stop poison, water and healing water. (the one shown in the screencap is healing water, but I tested with each)

4: Be sure to remove the stopper evenly, that is, all at once, unlss you are willing to use multiple layers of sealing liquid, otherwise it will not go in evenly and the water will flood around the seal.

It's occurring to me now that this is probably common knowledge for most experienced players, but hey, I spent an hour looking it up and found nothing sooo, yall're welcome.

 

If you want a cleaner solution, this mod: http://community.playstarbound.com/...-and-objects-formerly-lighted-platforms.3164/
...allows you to craft blocks that stop liquids but can be walked through. It's really neat. I like putting free-standing shafts of water in my base so I can swim to the next floor instead of using elevators or stairs.

 

Yeeaaah, I figured there'd be mods for it, but I'm playing on a group server and I get the feeling insisting on a mod would be taken poorly.

Plus, tbh, I'm not particularly patient when it comes to mods, especially when using them feels like I'm cheating half the time. I get this thought in the back of my head that effectively says "you may as well have used console commands at this point" and hell, even if console commands wouldn't have worked, it's the same general feel I get from it, like I didn't earn it