The invitation to post artwork of lighthouses came from Ray Monty (http://raymonty.blogspot.com/) . Maybe you have something to post to support his challenge. Do go and look at his wonderful photos.
Hopefully this image will enlarge with a click.My sketch is on a double spread in my moleskin book and was achieved with pen and wash while sitting on my jacket on the little (cold) path that ran round the back of the lighthouse and little cottage. Certainly didnt stay there long!!
Over to you Ray. .. just posted this little sketch to support your idea as I am sure others will post full size finished artworks.