How hot does fire need to be to light under water?

[Rin_The_Dragon_Empress]

Just out of curiosity how hot would fire need to be to accomplish such a feat? I'm aware that Thermite can do this, however this isn't done with thermite. It's just Luffy creating flames under water without any assistance from anything like that. For reference here's what it looks like.

 

[Crimson_Azoth]

Heat is not a factor. Fire needs unburned oxygen to fuel it, and to produce a flame. In water, said oxygen has alredy burnt, and therfor fire sufficates underwater. That there fire should be able ton exist, unless Luffy is able to provide it with a constant stream of oxygen

 

[Rin_The_Dragon_Empress]

Bump


Not sure how this is possible but I'd also assume you'd be able to get a temperature from this.