Draft Survey

Draft survey will determine the weight of any materials being loaded into or discharged from a vessel. OILLAB’s experienced and highly qualified inspectors can conduct draft survey to produce an independent draft survey report.

The vessel draft survey measures the displacement of the water both before and after the loading or unloading, with the resulting difference between the two displacements representing the weight of the cargo. Our surveyors work according to defined international guidelines when determining the weight of the cargo and consider several key factors while making their surveys. These factors include:

• Water density of the sea, river or other waterway
• Changes in the ballast quantity between initial and final draft readings
• Changes in the vessel’s consumables (e.g. Bunker fuel, potable water) between initial and final draft readings  

The accuracy of a weight determined by draft survey also depends upon the sea conditions  at the time of survey.