What Is This???

[Jeff T]

I went out to the boat today to pull the battery out and take a peek around. I"m going to be installing a second battery in a few weeks and I wanted to see what I've got to work with.

This may make me sound few newb like, which is really okay with me. But I have no idea what this is in the first picture.
Pic 1


Also, I know that the fuse in the second picture is for the factory installed amp. But can someone tell me why the red wires are fastened to the bolt?
Pic 2

[Coach]

2nd looks like a ground to me

[spharis]

1st pic is a 80A breaker. I don't know what it goes to, but usually that type is for audio. Those are more favorable because if you trip it, you can reset it vs. replacing a fuse.

The second are power wires. It looks like whoever installed opted to use that bolt as a power distribution point. Might want to redo that and have it straight off the battery.

Does a wire from the breaker run to that bolt as well?