I've been having an issue with the backpacks, but the biggest one here is that I can't access my backpack If I'm submerged in water. 

I recently had this as well. I drowned on my way to the underwater base, and now my backpack floats next tot he glass floor of the lab, unable to be opened. This happened a second time as I turned on the breakers, dying in the sunken, broken, lab. the backpack rose to the rock wall top, but remained stuck and unable to be opened.

After both of these incidents I have recently started seeing a new backpack item below the world and constantly sinking.

Today is the day my SECOND bag got stuck in a rock. One is by the bees (where the mosquitoes are in that water way) and the other is in a rock by the T-Rex. This is annoying. All that hard work gone. 😡😡😡

5 hours ago, MrBmore410 said:

Today is the day my SECOND bag got stuck in a rock. One is by the bees (where the mosquitoes are in that water way) and the other is in a rock by the T-Rex. This is annoying. All that hard work gone. 😡😡😡

Hence why BEFORE you go somewhere, you empty your bags of everything you are afraid to lose. I do that before every excursion because "Hey, you never know what will happen"

Why aren't you guys simply reloading a previous save? - My game autosaves every 5 minutes, so the most I'm going to lose is 5 minutes worth of gameplay. 

just use debug features (or whatever their called) to move your backpack to the starting cave