Underwater lighting device and underwater electronic device

Abstract

Provided is an underwater lighting device and underwater electronic device which are comparatively inexpensive yet durable enough for long-term use. An underwater lighting unit, which has an internally provided light sourceand a gas-tight casewith a windowfor allowing the passage of light from the light source, is connected to a land-based unitby a gas-sending tube. Air is sent from the land-based unitto the underwater lighting unitto maintain the pressure inside the underwater lighting unitat a value slightly higher than the water pressure at the location. A power line for supplying power to the underwater lighting unitand a signal line for controlling the emission of their light are installed in the gas-sending tube. Even if the gas-tight state of one underwater lighting unitis broken, water cannot enter the underwater lighting unit. Furthermore, the thereby generated bubbles help users locate the underwater lighting unitin which the gas-tight state has been broken. If a plurality of underwater lighting unitsare provided, they should preferably be connected in the form of a loop or matrix to the land-based unit