Draft Survey Calculator
Standard draft survey method — quadratic mean draft (hog/sag corrected), first trim correction, density correction, and final cargo quantity. Every step shown so you can verify against your vessel's procedure. Nothing is saved.
Step 1
Observed drafts (m)Forward
Midship
Aft
Step 2
Vessel particulars (from stability book, at approx. draft)LBP (m)
LCF (m from midship)
TPC
Step 3
Displacement at corrected mean draftLook up displacement in your ship's hydrostatic table at the corrected mean draft above, then enter it hereDisplacement from table (MT)
Actual dock water density (t/m³)
Step 4
DeductiblesLightship (MT)
Constant (MT)
Fuel oil (MT)
Diesel oil (MT)
Fresh water (MT)
Ballast water (MT)
Method: quadratic mean draft (Nemoto's formula) + first trim correction at LCF. This does not include the second trim correction (layer correction for change of TPC with draft) — for high-precision surveys, apply this manually per your vessel's hydrostatic particulars. Always cross-check against your approved draft survey procedure; this tool is for planning and verification support only.
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