In the 1st and 2nd episodes of the currently running season 4 of Star Wars: The Clone Wars, there were many underwater scenes ınvolvıng lightsabers. If you've watched those episodes, you'd have noticed that there wasn't any effect on water around the lightsabers.
From my point of understanding, lightsaber blades are thousands of degrees Celsius. That's why they could cut metal sheets.
And, with such high temperature, lightsabers could break down water molecules as well as vaporize them (distant molecules), which could create a whirlpool of powerful water currents around it. But nothing happened. Why?
Am I mistaken about temperature? Can the temperature of a lightsaber be controlled using the Force? What's your canonical explanation of this?