I have had my cobra fro more than 14 years (left the float tube for a drier ride) I have had countless trip in the ocean from San Diego to the central coast, and in many many lakes in nor Cal and the Central coast. And So Cal. The most scratches i get n mine com from the lakes and the rocky/ gravel shorelines, the sand really only seams to scuff and buff the bottom Invest in some good wheels and enjoy it, Though I have worn the keel, but I repaired that with a plastic sheet and welding rod, free from cobra, when I told them my issue. And that was 3 years ago. Pays to know how solder sheetmetal, Plastic is much easier than copper. Bottom line is use it,and enjoy and when you abuse it, fix it.
The way I see guys go thru kayacks her on this site amazes me. Some guys chang yack like socks...LOL..... For you are stll doing the same thing fishing, and enjoying the great outdoors a few nicks in life are not that bad. I store mine in the garage and always rinse the salt away. And when I store outside I cover with a tarp and remove all electronics. So yacks, they can last a long time.
Get out there and get some fish, and dont sweat the small stuff.
