When bringing the solar panel wires into the boat it's a good idea to enter the boat with a "drip loop". Deck and fitting leaks happen, it's just the nature of boats, and even "cable clams" can leak.
In the event of a leak the last thing you want is for the leaking water to migrate along the wire all the way to the controller, or another device near the wire that should not come in contact with water.
As always secure the wire well with wire ties on its path to the controller. This one mounted to the underside of the cockpit sole with Weld Mount tabs and wire ties.