im sure your boat isnt this bad, but i got a free 85 ski boat and the moron (co-worker) left it outside for like 5 years uncovered and he doesnt know how long it sat before he got it for cheap...
so the hull sides were brown and the rest white, well, the brown was light tan and the rest white/chalky to the extreme...
i got a quote from a huge name detail company in my boating town, he told me to use comet/ajax on the whole thing before i decide to bring it in and have it detailed/cut-polished.
i will say, it came out amazingly well. and then i just car wax-n-washed it... it looks really good...
he also said to do that if i have trouble spots of oxidation
but, its my fishing boat, so your results will vary