Friday Find: Gauging the tides

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The U.S. Coast and Geodetic Survey (NOAA’s predecessor agency) used this style of automatic tide gauge to record water levels until the 1960s.
Photo of a historic Standard Tide Gauge showing a ream of paper with a pencil in a holder that would record tides from the attached float..

Historic Standard Tide Gauge. (Image credit: NOAA Heritage)

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Black and white photo of a woman launching a weather balloon.

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Black and white photo of a woman launching a weather balloon.

The roll of paper turned at a steady rate by the timer and motor on the left side of the machine. A pen set in the holder above the paper traced the rising and falling of tides based on the height of a small float attached to it. The float was attached to the tide machine and housed in a stilling well, a vertical tube that sheltered it from any nearby disturbances in the water.

The clock on a historic Standard Tide Gauge. The brass plate is labeled, “USC & GS T-250” and a scrawled note in the lower left reads, “Repaired by Fowtz. Nov 66.”
The clock on a historic Standard Tide Gauge. The brass plate is labeled, “USC & GS T-250” and a scrawled note in the lower left reads, “Repaired by Fowtz. Nov 66.” (Image credit: NOAA Heritage)
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This Standard Tide Gauge replaced the first version of automatic tide gauges, invented by Joseph Saxton in 1851. Before their advent, tides had to be measured manually by placing a staff marked with units of measurement into the water.

Black and white photo of men installing tide staff during MacMillan Arctic Expedition on Schooner Bowdoin, 1925. For men stand on a rough pier, while one lowers a tide staff marked with measurements into the water.
Installing tide staff during MacMillan Arctic Expedition on Schooner Bowdoin, 1925. (Image credit: NOAA Central Library Historical Imagery)
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In the mid-1960s, the Standard Tide Gauge was replaced with an analog-to-digital recorder (ADR) tide gauge. These recorded water levels every six minutes, using a punch paper tape system, which could then be fed into a computer for processing. However, tide observers still needed to go out to tide stations and collect the data.

Photo of an Analog-to-digital recorder (ADR) tide gauge, showing two reels and a ream of punch paper tape on a roll.
Analog-to-digital recorder (ADR) tide gauge. (Image credit: NOAA Heritage)
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Now, everything is digital. NOAA currently uses an array of sensors at tide monitoring stations that transmit their data every six minutes to satellite and from there to NOAA’s database.

Have an idea for an artifact, photo, or document from NOAA’s history that you think we should feature in “Friday Finds!”? Send an email with a description and, if possible, a photo to heritage.program@noaa.gov.

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Black and white photo of a woman launching a weather balloon.