Create a grayscale portrait of a weathered old sailor with intricate wrinkles and a rugged beard, in the style of realism. The portrait should be highly detailed, showcasing every crease and line on the sailor's face. The lighting should be dramatic, casting shadows that enhance the textures and depth of the portrait. This artwork should resemble the realism style of artists such as Chuck Close, Caravaggio, and Rembrandt. Medium: Charcoal on canvas.