How to put a fire on water out? Use water of course.

[LightRoasted]

If I may ...

Leave it to the Daily Mail.

Circle of flames erupts in the Gulf of Mexico after a gas leak causes an underwater pipeline to catch fire
before ships rush to extinguish the blaze

Flames erupt in Gulf of Mexico after gas pipeline catches fire

Dramatic footage showed bright orange flames raging on the sea just meters from a state-owned oil drilling platform west of Mexico's Yucatan peninsula around dawn Friday.

www.dailymail.co.uk

It was dubbed an 'eye of fire' on social media due to its circular shape, while several
boats were seen rushing to suffocate the flames.

 

[Hijinx]

If it's natural gas you put it out by shutting down the pipeline.
Putting it out while it is still leaking can produce an explosion if the gas reaches a spark.

 

[Clem72]

I was told the ships do this to keep heat/debris away from them while they monitor the fire. They aren't there to put it out, obviously.