The picture tells a thousand words, and the video after the jump tells a thousand more. Golden Shellback is the name of the coating that is applied to these electronics that makes them impermeable to water. From their website:
“When applied to clean, moisture free surfaces, such as plastic, copper, aluminum, metal, ceramic, steel, tin or glass, the coating is transparent with excellent weather proofing and anti-corrosion properties. Golden Shellback coating has an excellent ability to repel oils, synthetic fluids, hazardous materials, dust, dirt and water based solutions. Low surface tension values, such as water and oils will bead and drain freely from coated surfaces. The process produces a uniform, continuous, near hermetic coating that resists rain and humidity. Electronics casually exposed to water continue to work even after exposure. The coating is readily applied and not generally considered to be removable. Repairs are made using abrasive methods. “
Strangely enough, Golden Shellback was created by the Northeast Maritime Institute, which is exactly what it sounds like! Skip forward to about 1 minute in to get to the good stuff.
via TechEBlog
PCB Coating is essential to protect against moisture, dust, chemicals and extreme temperatures from electrical failure.