Research Note

Running Lights

Bob Hill

Additional lights on commercial ships, such as tugs, indicate what they are and what they are doing at night or under less than normal lighting conditions. Although at sea and on "Western Rivers" lighting rules can be a bit different, sea lights for a tug would normally be one, two, or three white lights forward showing to two points abaft the beam on each side (225°).

At night or under less than normal lighting conditions, one white light such would be normal piloting light; two white lights would mean you have a short tow (200 meters or less), or are pushing another vessel ahead or alongside; three white lights would mean you have a long tow (over 200 meters from stem of tug to bow of towed vessel). On tugs with a tow, it has to also have a yellow light showing aft and above the stern white light in a 135° arc (to 2 points abaft the beam on either side). Of course towed vessels also must have their lights and for special conditions, such as submerged objects, other special lights.

There are other colors for forward lights that tugs might use, such as:
White over Red Pilot aboard
Red White Red (not good to see) vessel is aground; or
Red, Red, Red deep draft in area of shallow bottom and needs to stay in channel.
That's about all a tug would normally show, although some of the very large sea going tugs might just go to a length over 50 meters and then it requires two range lights forward, one on each of two masts with forward white light being lower than the aft one. These range lights are also 225° and forward only. There are also intensity requirements, but that's another tome :) .
{Bob Hill}

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