We tried a new product called Wonderfoam used to remove water spots and lime buildup from our boats. The product did an excellent job on fiberglass, stainless steel , and motor cowlings. We simply sprayed it on with bottle it comes in and in seconds after flushing with fresh water, it removed those ugly water and corrosion spots completely.
Wonderfoam did a better job than using Lime Away, which is used by a lot of the pros for cleanup at a comparable cost. Lightly spray on hard water deposits (lower units on motors, etc.), wait 10 seconds, and rinse off. Deposits wipe off with no effort! It is recommended that you follow the cleanup with a coat of wax for lasting protection. Wonderfoam is one of several products we tested for Larsen Sales, and found it to be the best buy of the lineup with the best results. The product may be purchased on their web site at www.larsensales.com