Poly-Planar's Platinum Series marine-audio speakers withstand severe exposure to sun and salt water. The Platinum line includes oval, panel and round models. Some of the speakers use the company's low-magnetic-field technology, allowing them to be placed anywhere aboard without jamming navigation instruments. The speakers have anodized aluminum grills, coated internal wires, polypropylene cones and Mylar tweeters for durable appearance and performance. Guaranteed for two years, sets start at $180. Poly-Planar Group LLC, Glen Burnie, MD; (410) 761-4000; www.polyplanar.com.