Various examples are provided related to boat loaders for trailers. In one example, a boat loader includes a primary tube extending between a first end and a second end and a light tube that can move within the primary tube. The light tube can include light elements extending along a portion of the light tube at a first end and a float attached to the light tube at a second end. The primary tube can be coupled to a trailer at the second end and the first end of the light tube can extend outward from the first end of the primary tube exposing the light elements as the primary tube is submerged in water and can retract into the primary tube as the primary tube is removed from the water.