Marine Set and Drift Correction Calculator
Explore the course and speed made good that hold a desired track under a constant current.
A QUICK WALKTHROUGH
How to use this tool
- Enter the desired track, STW, current flow-toward set and drift.
- Calculate the result.
- Copy the report or download it as TXT.
Formula and units
North is 0°; bearings increase clockwise from 0 to 360°. Set is the direction the current flows toward. Let δ = set − track, cross = drift × sin(δ), α = asin(−cross/STW). Course = normalize(track + α); SMG = STW × cos(α) + drift × cos(δ).
Scope
This chooses the branch with the vessel’s forward component along the target track. A forward solution requires |cross| ≤ STW and SMG > 0. This is a constant-current planar arithmetic demonstration, not safe-navigation advice; changing currents, wind, waves and other navigation factors are excluded. No parameters are preset.
Local processing
Your entries stay in your browser. Copy and TXT export include the inputs, formula and scope.
GOOD TO KNOW
Common questions
How should I use the result?
Use it as an arithmetic estimate based on your supplied inputs.