What all can you control with the Wetsounds EQ?

Boat Speakers?
Tower Speakers?
Subs?

All volumes separately?

I have been wanting to get something like this for awhile, no sense in project my music way behind the boat when we are just out riding around and vice versa. Could prob do it on my amps, but i don't want to have to crawl under the dash everytime i want to make an adjustment.