Search for "floating lights"
Coast Guard District narrative histories 1945
Lightships are actually floating lighthouses placed on station in locations along the coast where it would be impracticable or needlessly expensive to build a lighthouse. Quite frequently, they mark the approach to a port or the outer limits of outlying dangers. The forerunner of the modern lightship was the beacon boat which was originated in 1789. It was a small boat with colored daymarks on the mast and was used for about 31 years. There was no sound or light equipment on the beacon boat and consequently, it was superseded by the light and bell boats in the early part of the 19th Century. These light and bell boats were queer structures made of iron, flash-decked, turtlebacked and with a light or bell clappers fastened to the mast. Later daymarks were added. Light boats, or floating lights, as they were then called, were mostly anchored in inside waters and it was not until the development of the sturdier lightship that hazardous locations along the open coast were able to be marked.
The first light vessel (the No. 50) to be placed on Pacific Coast was stationed at the entrance of the Columbia River in 1892 and was propelled by sails. At one time during her history, she parted her moorings in a tremendous sea and heavy gale and was stranded on the shore near the mouth of the Columbia River. She lay there
(Image bottom left)
LIGHTSHIP #50 WAS THE FIRST OF ITS KIND ON THE WEST COAST. THE CIRCULAR SCREENS ON THE MASTS WERE DAYMARKS AS NO LIGHTS WERE EXHIBITED DURING THE DAY. AT NIGHT, 3 OIL LANTERNS WERE RUN UP EACH AUXILIARY MAST (AFT OF THE MASTS BEARING DAYMARKS.