Marine Stereos: Buying the Right Level of Waterproof Protection

Audio equipment in your car lives inside a waterproof, climate-controlled box. Your boat punishes audio components with spray, moisture, salt and UV radiation. The marine environment will kill an automotive-grade stereo in a few months or a single season under the best conditions, so saving money with a cheap car stereo is a mistake. What should you look for?

Marine stereos are rated either spray-resistant or waterproof. Look for CD slots that are sealed with rubber gaskets. Faceplates can (in theory) withstand either spray or complete immersion, depending on the receiver. In reality, marine stereos often aren’t rated by clear, objective waterproofing standards, but are “marinized” for surviving in salt-water environments. Some receivers, especially those from poly-planar and Fusion, come with a submersible IP waterproof rating.

Corrosion-resistant materials on good-quality marine units resist rust and salt water. Stereos include “conformal coating,” with a sealing coat of epoxy or urethane encapsulating circuit boards and processors. Plastic cases are UV-resistant. Speaker cones are polypropylene, not paper. Key metal components are often stainless steel. The wire is tin-plated, and contacts are often gold-plated.