Re: How do you get the salt water stain off of the hull?
Not sure if it will work for you, but I found Starbrite Hull Cleaner works great for river (tannin) stains. Take care not to get in on any metal, like the trailer the boat is on. I just wipe it on a ways along hull, then come back and wipe it again to watch the stain swirl away. Hose it off and water off the trailer too to ensure any on the trailer is rinsed off also.