I have allways purchased through the supplier for the projects that I have worked on, I am sure that there is a supplier in your area.
It works on piping that is submereged in waste water tanks, salt water is not as corrosive or toxic as that. I have used it to paint a couple of boats taht I used in the ocean and had great results with it.
As far as I know, it doesn't come in spray cans. On the project that I am on we are getting it from Steelcon Ind. Coatings.
I have never tried to purchase without going through a vendor on one of my projects but it is outstanding paint.
sorry if this is no help.