Definition of Plimsoll line in English:

Plimsoll line

(also Plimsoll mark)


  • A marking on a ship's side showing the limit of legal submersion when loaded with cargo under various sea conditions.

    • ‘Belisha beacons, bobbies on the beat, Big Ben, a ship's Plimsoll line - all are familiar terms with their origins in the names of notable MPs of their age.’
    • ‘Life-jackets, boats, signals, Plimsoll line, radio, all made navigation safer.’
    • ‘It does not have a Plimsoll line like a cargo vessel.’
    • ‘In the nineteenth century, Plimsoll was credited with naming the Plimsoll line, a line that shows the depth to which a properly loaded ship can be immersed in water without sinking.’
    • ‘Below this a single Plimsoll mark, ‘VI ‘, showing the draft of the tug in feet.’’


Named after Samuel Plimsoll (1824–98), the English politician whose agitation in the 1870s resulted in the Merchant Shipping Act of 1876, ending the practice of sending to sea overloaded and heavily insured old ships, from which the owners profited if they sank.


Plimsoll line