So, air tanks are so difficult to find, yet it only can be used for 3 times only.

By logical air tanks should be self-refilled when we're on surface. This is a suggestion for developer. 

How you guys doing ?

i almost found all of the items in stranded deep, except mysterious box. Getting bored already, sometimes i paddle to the middle ocean and bring a whistle pretend like i am in a movie life of pi, After the sunset i go back to my basecamp. i cook food, and sit on my bed watching the sky to look a flying plane and use my flare gun. no shits happen, i have a total 3 flare guns. So i'm still waiting for a rescue, i'm hoping a flying plane detect my flare coordinate and report it to the air traffic controller.