Abstract: A bumper for a boat dock is provided which is durable, resilient and visible at night. The bumper is constructed of an expanded polymer such as polyethylene or polypropylene. The bumper is preferably made of translucent polyethylene foam with a density of between 2 and 4 pounds per cubic foot. When polyethylene foam is subjected to impact, it absorbs the force of the impact and returns to its original shape. The present invention includes a light for illumination of the bumper itself or illumination of an area immediately adjacent the bumper. A slot in the bumper is provided for accepting the illumination source. If the bumper is translucent, as with white polyethylene foam, the illumination source may be inserted into the back of the bumper such that light is emitted through the front of the bumper. If the bumper is opaque, the illumination source may be inserted into a slot in the bottom of the bumper so that the light is emitted from the bottom of the bumper.