Illumination systems that include a plurality of illumination devices disposed within a water environment. Such illumination devices having a tube filled with water, at least one light source positioned to project light into the tube, and connected to the illumination devices via light carrying connectors, include one or more voids within each tube wall which extend substantially longitudinally and cause light incident below a critical angle to be reflected hack into the tube. Projected or reflected light above a critical angle that strikes a portion of the wall without a void is transmitted through the tube wall. By adjusting the ratio of voids to non-voids light can be delivered in a controlled manner.