iRegattaLights is an overview of lights and shapes use at sea to signal the type of craft and activity, as described in the collision regulations.
If you see a light combination at sea at night, you can find it in the "Night" table and click it to see a 3D view of a ship displaying the lights and a description of the rule.
At daytime special ships are displaying shapes instead of lights. You can find them in the "Day" table and click it to see a 3D view of a ship displaying the shapes and a description of the rule.