In my first post on this blog, I say: I l-o-v-e sailing becuase there is so much going on. This includes lights. We've had three night sails (so far) this season – I absolutely love those too.
There are three standard light settings on a sailboat like Calpurnia's Love: Anchor, Steaming (Motoring), and Navigation (Sailing). Note the center of the light switch icons below.
When there is so much going on, you need documentation such as the USCG Rules and Regulations Handbook to inform. Let’s talk about Part C – Lights and Shapes.
International Rule 30 covers Archored Vessels, stating: “A vessel of less than 50 meters in length [like Calpurnia's Love] may exhibit an all-around white light where it can best be seen…” In Calpurnia's Loves' case, “where it can be best be seen” is the masthead light. Toggling the anchor light switch turns on the all-around white masthead light.
International Rule 27 covers Sailing Vessels Underway, stating (I paraphrase) that a sailing vessel underway shall exhibit sidelights and a sternlight. These lights may be combined in one latern at or near the top of the mast (where it can best be seen) for a vessel of less than 20 meters in length. Calpurnia's Love uses this “combined” configuration, displaying red to starboard, green to port, and white to the stern. When a vessel sees red and white (for example), they know the other boat is headed to port. Toggle the switch to the right for this configuration.
International Rule 25 covers power-driven vessels underway, stating (paraphrased) that vessels under 50 meters are obliged to exhibit sidelights and a sternlight. We almost alwasy moor under motor so when we switch from sailing to motoring, we're suppossed to change the lights by toggling the switch to the left. This turns on the steaming lights and the masthead all-around white.
Here's a video on the subject:
Calpurnia Republic 