MARITIME – AFETY, URVIVAL & RECUE CALCULATOR
Datum Drift Sar
A precise tool.
What is the Datum Drift Sar & How does it work?
When an object is lost at sea, its subsequent location is governed by the combined effect of leeway – the sideways motion caused by wind on the exposed surface – and the ambient ocean current.
Leeway is usually expressed as a speed (knots) and a direction relative to true north, while the current is described similarly. By treating each as a vector, the total drift can be obtained by vector addition over the elapsed time.
The resulting drift vector provides both a distance and a bearing, which can be projected onto the Earth’s surface to estimate a probable search area for SAR operations.
V_{total}=\sqrt{(V_{L}\sin\theta_{L}+V_{C}\sin\theta_{C})^{2}+(V_{L}\cos\theta_{L}+V_{C}\cos\theta_{C})^{2}}\times t
V_{total} = drift distance (NM)
Parameters
Result
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Frequently Asked Questions
How do I input the leeway speed and direction?
Enter the leeway speed in knots and its direction relative to true north.
What is the difference between leeway and ocean current?
Leeway is the sideways motion caused by wind on an object, while the ocean current is the flow of water in a specific direction.
How does this calculator account for time elapsed?
The calculator uses vector addition over the specified elapsed time to determine the total drift.
Can I use this calculator for multiple objects?
Yes, you can input different leeway and current values for each object separately.
What is the output of this calculator?
The output provides both the distance and bearing of the total drift vector.
Is there a limit to the time period I can calculate?
No, you can input any time period for which you need to calculate the drift.
How accurate is this calculator in real-world scenarios?
The accuracy depends on the precision of the leeway and current data inputted; it provides a model-based estimation.
Results are for informational purposes only and do not constitute professional advice.