I’ve noticed that when you plunge into the water in Subnautica 2, there are barely any bubble or foam effects displayed. Likewise, when you climb back out of the water, there’s hardly any water visible on the goggles. Aside from a few bubbles when entering the water or a drop or two after exiting, the FX side of things is practically only noticeable through audio. This makes it feel less like I’m actually swimming underwater, and it detracts from the underwater experience of this otherwise amazing game. Please, don’t underestimate the air to water (and vice versa) transition FX!
Add foam, many more bubbles, and streaming/dripping water during the transition. I’d only apply these FX when entering or exiting open surface water, not when transitioning to or from a Hatch, since your own lore states that the membrane only allows crew and cargo through. May I suggest: take some inspiration from YouTube clips for this. Search for “pov jumping in water”.