At least at the first stage, there's something quite comfortable about being a professional Scandinavian diver. Gives off real My Summer Car vibes. I liked the commitment to the aesthetic and setting, and it definitely gave the game a fun appeal and a good framing device to start the plot. 

The core mechanic - survival through managing air - is paired pretty well with the surrealistic turns the game takes, although once onto the ship the tanks were generous enough to limit the challenge. There's enough turns and corners in the level design to add a bit of an exploration element too. 

And as a horror game! The subtleties are the most important thing. I like how there were no obvious scares and just a slowly-developed, building dread. I think the pairing with the sense of unreality really made this game something more than just a generic deep-sea scarefest. Done really well. 

Just some points of constructive criticism: 

• I love how you play with light and shadow mechanics to lure the player into the scares. The torch flicker is devious. I'd really encourage you to find other ways you can 'trick' the player into letting their guard down, or creating a sense of discomfort rather than the dimly lit torch effect, which only so much can be done with. 
• Ambiguity is a great driver for narrative, particularly in terms of creative something more nuanced, but it would be a little nice to have some contextual/environmental opportunities to understand what is going on, setting wise. I'd love to just get a tiny hint of what the hell is going on! Or maybe I don't want to know...

I did a gameplay video below: 

This is a great achievement and addition to the jam. Thanks for submitting this!