Charles 30 Amp 125 Volt to 50 Amp 125/250 Volt Straight Marine Shore Power Products. Dependable, secure connections between your onboard electrical system and the shore outlet are critical. Charles utilizes more than 35 years of in-house molding and metal stamping capabilities to offer a wide range of high-quality, corrosion-resistant shore-power cable products that ensure the safety and reliability of your ship-to-shore connections.