Maritime glossary · Plimsoll Mark
Load Line
The marking on a ship’s hull that shows the maximum legal loading depth for a given season and water density.
Definition
The load line, named the Plimsoll mark after the reformer Samuel Plimsoll, is the circle and horizontal lines painted on a ship’s side that mark the deepest a vessel may legally load. Separate lines cover tropical, summer, winter, and fresh water conditions, because a hull floats higher in cold dense seawater and lower in warm fresh water. The International Convention on Load Lines makes the marking and its certificate mandatory, and overloading past the mark is a Port State Control offence.
Worked example
A bulker loading in a tropical fresh-water river to its TF (tropical fresh) line will rise to its summer line by the time it reaches the open sea, where the water is colder and saltier.
How Vessel Hunter uses Load Line
The load line is the legal ceiling behind the deadweight figure on every Vessel Hunter spec sheet.
Related terms
- Freeboard
The distance from the waterline to the main deck, a direct measure of a loaded vessel’s reserve buoyancy.
- Draught
The vertical distance from the waterline to the deepest point of the hull, the constraint that decides which ports a loaded vessel can enter.
- DWTDeadweight Tonnage
The maximum weight in tonnes a vessel can carry (cargo, fuel, ballast, crew, stores) without exceeding its load line.
The bigger picture
Load Line is one piece of the commercial maritime picture Vessel Hunter pulls together for shipyards, suppliers, service providers, and port agents. Every vessel record bundles AIS, ownership, inspections, dry-dock history, casualty record, classification status, and a verified contact for the operator decision-maker behind the ship, so the team that reaches out first wins the work.
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