The boat that I just bought has had a battery boil at some point due to extended lengths of charging. It's quite dirty on the gas tanks and I've noticed some corrosion starting on some screws, hinges, metal parts in the back. What is most effective cleaner to clean this up? CLR? Would you take everything out and clean from top to bottom or just the visible areas? I'm afraid if I just clean what I can see that later down the road I will fight continual corrosion issues. Thanks in advance for your advice.

Okie

https://www.youtube.com/watch?v=OJwVwvEHh3Q
This is a good little video on cleaning batteries,..also once cleaned I always put a light coat
of vasoline on all the wire ends and posts. always vent your battery compartment when charging, I just open the
door. Fumes over time in a confined area can cause corrison also. Wear rubber gloves and eye protection.
run the water gently to wash away the yucky. Remember you're washing away battery acid, clean in a safe place.

Baking soda and water to neutralize acid. Then hose out, dry and spray everything with Corrosion X.
After neutralizing inspect what you can see, if anything needs replacing due to the corrosion, then pull everything and replace as needed then spray with corrosion X.

this ^^^

OK, great. Thanks for the advice.