> Having all of this in mind, I would go further and propose to regulate by law changing the material of the deep sea submarine ballasts.

Which country's law? There are many of them.

> 1) Lesser impact on deep sea ecosystems. No human trace left behind.

There's barely any submarines around. This is a drop in the bucket.

> 2) Improved economics?

If it improves economics, why do you need to force people with regulation?