Plimsoll line

The Plimsoll line is the mark on the hull of a ship that shows where the waterline is when the ship is at full capacity.

The official name is the international load line, since the Plimsoll line is an international load limit standard. It was named after Samuel Plimsoll, who instigated the passage of the Merchant Shipping Act of 1875, which established the marking of a load line on every cargo ship. This was to prevent the practice of launching deliberately overloaded "coffin ships", which were intended to sink so that the owner could collect the insurance money.

The letters on the load line have the following meanings:

• TF - Tropical Fresh Water
• F - Fresh Water
• T - Tropical Sea Water
• S - Summer Sea Water
• W - Winter Sea Water
• WNA - Winter North Atlantic

An early type of training shoe with a canvas upper and rubber sole, developed as beachwear in the 1830s by the Liverpool Rubber Company (later to become Dunlop), was first called the 'sand shoe', and in the 1870s acquired the nickname plimsoll because the coloured horizontal band joining the upper to the sole resembled a Plimsoll line.