Thanks, colors are totally mine. I would change shapes to show perspective and form, but I wasnt really thinking about that while making that drawing. 

And I looked up for aqualungs, but when I tried to fix it and make more realistic - the whole drawing was screwed. I just dont liked it anymore and leaved that idea, but I'm actually trying to pick interesting details and shapes from references whenever it's possible :)

Agree that it's totally hard to join the community. I really like your limited palette in this piece. You've got a great technique!

Maybe try skewing some of the shapes to fit to the cylinder (like the circle for the eye, for example). Try to work from references where you can!

Did you pick these colours yourself?
 

Thanks! Before I used to paint in soft palettes, so this was kind of expirement to me :)

A nice first piece! Very sharp!