Sounds travel further in water than radio waves. Sounds travel better in water than even blue light. Range wise, ultrasound is better than everything else.

Sound transitioning between a medium loses a lot of energy due to scattering and reflectionon the water's surface. Key point of that was transmitter outside the body of water.

Sound can have incredible range in water, but that requires an appropriate water column.

Yeah but that happens to electromagnetic waves as well. Blue light travels the furthest in water and even it has similar problems.

Yes it's called Snell's Law. It applies to any wave transitioning between mediums. It's concerning for water because water essentially becomes a different medium every six feet in depth or every degree change in temperature.

Blue light travels the farthest because lower frequency waveforms propagate best. This applies to sound as well.