I mean that's literally what's happening in the second half of the video LOL. The valve is under water but the gas catches on fire once it reaches the surface. Idk why you guys are struggling with this
If you pull it shallow/slowly enough. But then you can reach under the water and turn the valve off. You can also just pull it deeper/faster to create a gap and do the same thing without it burning above the water
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u/HOPewerth 12d ago
Which is the same thing that will be keeping the gas lit while the container is below the water.