How do you 'Explore the Sunken Base'?

[JonesyLax91]

I've turned on all three breakers/dials, the underwater trap door opens up, but there are only two doors open in there. One leads to the storage area/place where you flip the switch to start activating the breakers and one leads a little way into the base but all other doors are locked.

On videos I've seen on YouTube (must be an older patch) there's another door open in the trap door room that isn't open in mine. I've explored the hatch under the concrete lantern-type thing in the pond and the door is locked. I'm just about to try the vertical hatch by the fish bowl thingy but thought someone might have some insight?

[pcdeltalink]

There is a way through in a flooded room that’s past a flooded hallway there is a hole in the floor that gets you around one of the locked doors.

I redid the underwater lab after the recent update so if you want a more up to date video I offer mine. Skip to 16:30 for the hallway I mentioned. Go to about 15:30 if you need to see it from the beginning of my time in the lab.

https://m.youtube.com/watch?v=Q_kByLIhi3w&t=650s

[JonesyLax91]

Many thanks, marking this as the answer!