Hahaha. Yeah, I think it was a bad design choice not to allow oxygen away from the boat, got a lot of feedback on that. It is not intuitive at all.
I will probably change that in the future, when I have more time.
About a win condition, I was thinking on allowing the player to get in the boat whenever they wanted and exchange the points for perks or customization, but I had to cut that idea off.
Thank you for the feedback!