Our test group included five products from the marine industry and one home remedy—water and vinegar.

Most of us are finicky enough with our sailboats that we value having just the right tool for the job, but water spots? Do we really need specific products for removing these harmless blemishes?

Because of our skeptical nature, we did a bit of Internet research and found that there are actually quite a few people staying up late worrying about water spots. For those poor souls, it's nice to know that there are several products formulated specifically to remove those spots from boats. We tested five of them, along with a home remedy that we've heard works just as well as all the store-bought stuff.…