It's a commonly known fact that whale song travels huge distances. In fact apparently before the oceans were so noisy they could communicate over 10,000km!

However, whales are very big! They can create very loud noises, far louder than any being of 2 metres. In addition whalesong is typically around 10-40hz and is lower than a human is capable of producing. I'm unsure if this has bandwidth implications.

Assuming:

* A creature of about two meters in length
* Wanting to hold a normal conversation spoken (in their own language but basically humanlike speech)
* Assuming they can't open their mouths throat type sounds are permitted/encouraged
* The creature must also be able to communicate with humans (speak a human language as a second language)

What is a reasonable range they could "shout" to their friends underwater? 100 metres? 400? A mile!?