This essential practical guidance issued by Britannia P&I Club provides an overview of the key concepts and considerations involved in conducting a draft survey for ships.
Draft surveys play a crucial role in determining the quantity of cargo loaded onto a ship. While based on the simple principle of Archimedes’ law of floatation, the calculation process can be complex due to the ship’s shape, non-linear changes in draft due to hog and sag, and external weather conditions.
Simply put, the weight of the cargo is calculated between the difference of the weight of the ship before and after loading. Allowances are made for ballast and other known weights.
Disputes can be prevented by managing the risk at the time of the fixture by clearly indicating which figure would be binding.
Download the guidance: Draft Survey Practical Guidance