Well, after owning my pool for two years, and going through just about every other kind of problem, I noticed a rust spot on the wall of my vinyl liner yesterday. "What could cause that?" says I. Ahh, well as it turns out, it's a cut about 1/2" long, and the steel wall behind the vinyl is rusting and seeping through the cut.
After doing some searching here, I found a lot of solutions, but most of them were plain blue patches, which would stick out like a sore thumb on my patterned liner. I noticed one person mentioned Tear Aid, which is self adhesive and clear, and after visiting their website I found that my local canoe and kayak store carries it (they sell it for patching drybags and inflatable boats).
I grabbed the dog and hopped in the Jeep and headed there this morning, and bought a box for $9. Tear Aid makes two products - Type A for cloth, and Type B for vinyl - you want to make sure to get the Type B for a pool liner.
Unlike competing products that you have to slather with vinyl glue, the Tear Aid product is self adhesive, like a tape. It has a backing that you peel off before adhering it, and yes, it adheres under water. I dug the Scuba mask and snorkel out of the closet so I could see what I was doing, cleaned the area of the cut, and applied a rounded patch that I'd cut from the small sheet that comes in the box, using a credit card for a squeegee to make sure I didn't have any water bubbles underneath it. Tear Aid cautions that it doesn't develop full bond strength until 24 hours, but this stuff is STUCK right away - if it continues to gain strength over the next day, it's going to be awesome. One tip I can offer is that the backing is paper and if you get it wet prior to starting to peel it off, you'll never get it peeled. My first patch blew into the pool while I was getting ready and I had to go cut another.
Check out their website for details. Tear-Aid Repair Patches - Home
Oh, and made in the USA, my kind of stuff.