Ballast

Αυτό το λήμμα δεν έχει μεταφραστεί ακόμη και εμφανίζεται στα αγγλικά.

Ballast is weight — in modern ships, seawater pumped into dedicated ballast tanks — carried to keep a vessel stable, properly trimmed, and deep enough in the water when it is not carrying cargo. Without ballast, an empty ship would ride dangerously high, with its propeller partly out of the water and excessive windage.

A voyage leg performed without cargo is called a ballast leg or sailing “in ballast”, and minimizing ballast time is central to commercial ship operation: a ship earning freight only when laden wants the shortest possible repositioning voyages. Market analysts track the ratio of laden to ballast voyages as a signal of fleet efficiency and market tightness.

Because ballast water taken on in one part of the world is discharged in another, it became a major vector for invasive aquatic species — leading to the IMO’s Ballast Water Management Convention, which requires ships to treat ballast water before discharge.