Fiber-optic cable is dispensed underwater into a trench from a vehicle moving along the bed of the body of water. The various embodiments typically require the use of an array of backlighting LEDs disposed beneath and configured to emit light in the direction of an overlying LCD or LCD panel. A slot is provided between adjacent pockets to provide a thermal break. In this structure, the light travels parallel to the optical axis. The outer chamber including a Faraday Cage.