Photo Study - Lighthouse by Suzanne Friedrich

the photographer who took this can be seen here

This cool photo can be emulated using gimp with the right tools. The lens flare combined with color modification tools could create your general "guiding light" shape. With that, you could create a layer mask and fill the layer white. Alternatively, another effect that may work is very much like what I did in my sun rays using gimp tutorial. only instead of using the burst for the sun, you could use this gimp effect to create the burst for the lighthouse.