Do I need a permit for putting retrievable sensors in ocean (Atlantic)? The project would be to place about a dozen sensors in "swarm" fashion and have them collect data from the Atlantic ocean.

The sensors would be about the size of a softball and would be retrieved days later after data is collected.

I've been looking at regulations and permits needed for this but only find construction based permits for building homes or factories near the ocean.

Is there a permit I need to pull for this or a body who regulates this kind of research?

And would a different permit be needed if the sensors weren't meant/or unable to be retrieved?
It depends where you live as laws verry from country to country. Just ask your local lawyer or law enforcement official. It may also depend on what data you are recording