Abstract: It is well known that light attracts fish at night, and that any artificial fishing light attractor is preferably submersible to avoid significant amounts of light being reflected off the surface of the water. Single-use glow sticks are known to be used as submersible fishing light attractors; however, these cannot be turned off, can be used only once, and are often of relatively low intensity. The present invention provides a powered light source with an intensity higher than conventional glow sticks that may be attached to fishing lines. To achieve this, the light source is configured such that, when the light source is placed at depth, external water pressure acts to increase sealing against ingress of water.