Article by Capt. Mark Sampson
Over the Labor Day weekend, I took a couple from California out for a short cruise to see the beach and watch the sunset from the ocean. Unfortunately, just prior to our departure, a blanket of thick clouds moved in from the west and pretty much wiped out any hope of seeing a painted sky, and as the mostly grey, evening morphed into a very dark night, a little earlier than normal, I was happy that the vibrant lights of Ocean City were there to add color to an otherwise black horizon and give my passengers something pleasant to view.
It was still more “dusk” than “dark”, but certainly after the official time of sunset for that day, when I noticed a number of boats returning home from offshore. At first sighting each one would appear as a single spot of light on the horizon that flickered on and off as the vessels bounced over the swells. But as each one got closer, the image would sharpen to eventually reveal the multiple lights of red, green and white of a powerboat underway. In the fading light, I also took notice of a few boaters coming in who had apparently neglected to reach down and flick their navigation light switch to the “on” position when it started to get dark. Of course, I couldn’t see them until they were very close by, and I wondered if they knew that navigation rules require that boaters have their lights on, not just when it’s “dark,” but from “sunset to sunrise and anytime during periods of decreased visibility”, such as during the fog.
Unlike the headlights on our cars, navigation lights on a boat are not intended to help the operator see what’s up ahead, they are simply there to make other boaters aware of our presence and give them an idea of what we’re doing and which way we’re pointed, which ultimately should allow skippers to steer clear of each other and avoid having a very bad night on the water.
The average, small runabout typically comes equipped with a combination red and green light that many will call a “bow light” or “running lights” and a single white light towards the stern often referred to as a “stern light” or “anchor light.” But technically speaking, those terms are incorrect and misleading as proper descriptions of the function of the lights and the messages they are intended to convey when in use.
According to both the International and the Inland Rules of the Road, all power-driven vessels are to display a red light forward on the port side and a green light forward on the starboard side with each light having an arc of visibility of 112.5-degrees. The red and green lights are known as “sidelights” and are positioned such that if you are looking at the port side of the boat you cannot see the green light and if you are looking at the starboard side of the boat you cannot see the red light. Only if you are dead ahead of the other vessel will you see both red and green lights at the same time, that way you know for sure when another vessel is pointed right at you.
Power vessels are also required to display a white, “masthead light” pointing forward with an arc of visibility of 225-degrees. This light is to be higher and aft of the sidelights and, if you notice, it has the same arc of visibility of the two sidelights combined. Therefore, anytime you are looking at an underway power boat from the side or the front, you will see a white light along with a red or green, or both a red and green light. Masthead lights are only used on powerboats, so if you see only a red or green light, but no white light, then it should be a vessel without power such as a sailboat or perhaps a barge.
All power vessels are also required to display a white “stern light” pointing aft, with an arc of visibility of 135-degrees. Since the red, green and masthead lights only project 112.5-degrees from the bow, if you approach another vessel from the stern the only light you will see is a single white light.
An “anchor light” is a 360-degree white light that is only to be displayed when a vessel is actually anchored. So a single white light at night can either mean the stern of a boat underway or a boat that’s stationary and on anchor. Either way, a single white light will always warn another captain to pass with caution.
As you can see, the navigation lights on vessels are designed to tell other mariners not only that “I’m here”, but also give observers some idea what the other boat is, and what it’s doing. So if you’re now concerned that your 20-footer is not in compliance with the rules because instead of having two separate side lights, a masthead light, and a stern light it only has a single red and green light on the bow and a 360-degree white light on the stern - don’t worry, the rules also state that on vessels under 12-meters, the two side lights can be combined into one red and green light, and the 225-degree masthead light can be combined with the 135-degree stern light to make a single 360-degree all-round white light. Choosing that option makes it easier for small boaters to find a place to mount the required lights while still projecting the same light patterns and colors for other boaters to see. It can also save you the aggravation of maintaining and replacing so many light bulbs – just don’t forget to turn them on!
Captain Mark Sampson is an outdoor writer and captain of the charter boat “Fish Finder”, docked at the Ocean City Fishing Center.
