According to IMO resolution MSC.137(76) “Standards for Ship Manoeuvrability” adopted on 4 December 2002.
- Advance – The distance travelled in the direction of the original course by the midship point of ship from the position at which the rudder order is given to the position at which the heading has changed 90° from the original course.
- Tactical diameter – The distance travelled in the direction of the original course by the midship point of ship from the position at which the rudder order is given to the position at which the heading has changed 180° from the original course. It is measured in a direction perpendicular to the original heading of the ship. Typical values are tactical diameters of 4.5-7L for slender ships, and 2.4-4L for short and full vessels.
- Test speed – A speed of at least 90% of the ship,s speed corresponding to 85% of the maximum engine output.
- Track reach – The distance along the path described by the midship point of a ship measured from the position at which an order for full astern is given to the position at which the ship stops in the water.