New Marine Overcoat Sea-Slide™ Increases Speed, Saves Fuel
—Literature Available Hydromer, Inc., has developed a water-based urethane drag-reducing overcoat called Sea- Slide™. Designed for the commercial market, it is an easy-to-apply finish that reduces friction between the boat's hull and the surrounding water and is based on the principle that a surface where water skins produces less drag than a surface that causes water to bead.
Sea-Slide actually absorbs some of the surrounding water in an ultra-thin coating that binds a layer of water around the hull. Because the contact angle between the hull and the surrounding water is close to 0 degrees, water turbulences and drag are greatly reduced. In-use tests report drag reductions from 11 percent to 17 percent at speeds above 7 knots.
Gerald H. Gumpert, director of sales and marketing, said: "In-use tests by commercial fishing vessels have reported impressive fuel savings with Sea-Slide overcoat. In one report from the Gulf of Mexico, the skipper stated that at a constant 1,350 rpm, his speed increased from 6!^ knots to 1% knots, an impressive 15 percent fuel savings." This confirms controlled experiments in which a weighted dinghy was towed around a quiet lake. A force gauge in the tow line indicated the force required to pull the boat before and after the coating was applied. Results indicated that at increasing speeds, a more substantial reduction in drag was attributed to the coating. At 20 knots, the coating reduced the water drag by a substantial 17 percent, while at lesser speeds, where drag exists, the Sea-Slide coating provided an 11 percent benefit.
Because of the unique properties of Sea-Slide, it permits normal leaching of anitfouling toxins and does not inhibit antifouling bottom finishes. According to the manufacturer, Sea-Slide rated excellent and superior over all kinds of antifoulant coatings in a comparison test with other bottom overcoat speed coatings.
The manufacturer also says that because Sea- Slide is a water-based urethane coating, it is easy to use and clean up after. There are no hazardous chemicals or complicated mixing required, and it may be used directly from can, applied by brush, roller or spray. It stays smooth and dries to the touch in 30 minutes, and cleaning is easily done with plain water. After curing (about three to four hours), the boat may be launched immediately or kept from the water indefinitely without losing its unique properties. Sea-Slide may be applied over any bottom, with or without antifouling finish. It is economical to use, and one gallon covers approximately 750 square feet and is available in quarts or gallons. A single quart can covers the average 25- foot boat hull.
For complete information and literature on Hydromer's new Sea-Slide marine overcoat,