Underwater volcanoes are formed at 'hot spots' in the Earth's mantle, as in the Hawaiian Island chain, or in deep sea trenches, where oceanic crust is subducting under oceanic crust, melting when it reaches the mantle, then erupting as a volcano.
neva dat
it forms underwater starting with a big eruption then it shoots out lots of lava like regular ones.
Underwater volcanoes form islands.
No, they form at boundaries.
Yes, most volcanoes are located under water at the mid-ocean ridges. They can be one of the reasons that tsunamis happen.