Q: I just had my boat waxed, which removed all the black water streaks, but it’s only been a few weeks and now most of them are back. Why are they back on a freshly waxed boat?
A: Black streaks are made by rain water that runs down your boat in certain areas, such as off the back corner of your canvas enclosure, from a stanchion or a windshield wiper base, just to name a few places (a very few, actually). Any vertical surface can show black water streaks after it rains and they will come back after each time that it rains. The more dirt and particles in the rain, the darker those streaks will be. Waxing your boat won’t prevent them from showing up after it rains, but it will make them much easier to wash off. You can even wipe them away with your finger or a microfiber cloth. When you wash your boat, they’ll come off with soap and water and the soft deck brush.
However, as the wax wears off on your boat, those water streaks will be harder to remove, especially if you don’t wash your boat on a regular basis. It usually takes about six to nine months for wax to start wearing thin and for black water streaks to become more stubborn. The more porous the gel coat, the more likely stains, streaks and marks will “soak in” to the gel coat and require more than just a mild cleaner or soap to remove.