Hello,
as we well state in our bio, we are an abicious group of students from Andorra with the will to create our very own sea buoy to study the sea itself allong with the water's contents. One of our major concerns now is to find a microphone that is waterproof to be able to study any type of marine sounds to amplify our ambicious reserch.
We would appreciate very much your response and collaboration to fulfill our self-starting project.
An Arduino does not have the capacity to do much more than detect the presence or absence of sound, and even that is very limited.
Depending on what you want to know about the sounds, there are many other devices out there that might be helpful to you. Keep googling!