Vessel Trim Calculation

Vessel trim calculation involves determining the difference in draft (the depth of the vessel below the waterline) between the forward and aft ends of a vessel. It is usually expressed as a percentage of the vessel's length between perpendiculars (LBP) or as an angle of inclination of the vessel's longitudinal axis.

To calculate vessel trim, the drafts at the forward and aft ends of the vessel are measured and the difference between them is calculated. The formula for vessel trim in percentage is:

Trim (%) = (Draft Aft - Draft Forward) / LBP x 100

Where:

Draft Aft is the depth of the vessel below the waterline at the aft end

Draft Forward is the depth of the vessel below the waterline at the forward end

LBP is the vessel's length between perpendiculars

For example, if the draft at the aft end is 6 meters and the draft at the forward end is 5.5 meters, and the vessel's LBP is 100 meters, then the vessel's trim is:

Trim (%) = (6 - 5.5) / 100 x 100 = 0.5%

This means that the aft end of the vessel is 0.5% deeper in the water than the forward end.