I remember seeing an ad for Brians Enterprises in either buy and sell or Pennysaver, I know one of my co-workers bought some for his boat, he said it works great but is really really expensive like 22 bucks a pint?
The POR 15 website indicates that Kona Marine Supply (808) 329-1012 is a local distributor. I remember getting information from Kona Marine. However, POR 15 is available at Redline automotive. I saw it on the shelf and bought a pint.
Check the PennySaver or similar paper. Brian's Enterprises is listed in the back pages. He sells or used to sell POR-15 directly. I met the guy and talked to him at length. Purchsed POR-15 from him. Very nice, personable buy. Has a nice 68/69 (can't remember) Camaro. You can also get it at Redline Automotive.