Gouge in coolant hose

If that is just an indentation where the rubber was compressed, you might be OK.
If it is actually cut/damaged or material is missing: if it is bad enough that you have to ask, it is bad enough to be replaced.
Otherwise, it is like asking, "How far can I push a pin into a balloon before I have to worry?"

If that spot springs a leak in flight two years from now, are you going to be alright with that?

Yes, the material is actually missing, not just compressed. 
Thanks for responding, I appreciate it. 

I agree with Bill. replace. It's better to error on the side of safety than wish you had later if it turns out to not be a good decision. You may even sleep better knowings it's replaced. :) 

Thanks, Roger.

Afterward, I suggest you get yourself some anti-abrasion tape for those little spots where hoses, wires, ties, etc. unavoidably rub against each other, e.g. Painless Performance 72022