A system for controlling a string of lights, where each light or group of lights has a microcontroller for controlling their brightness and color. The power supply converts AC power to DC power. The system and method prevent a siphoning effect, whereby leakage of water into the exhaust valve is minimized or prevented. Cart 10 is attached and detached with one hand without tools. The method includes positioning an energy transducer below overhead wave action and at a depth and orientation substantially responsive to reciprocating water surges arising from the overhead wave action; and powering the energy transducer by the surges in alternating first and second directions to generate electrical current.