Oil drift indicator

Where oil drift modelling data are not available, the following can be used for calculating drift of an oil spill:

- If no wind, oil will drift with 100 % of the surface current speed and in the direction of the current.

- If no current, oil will drift with 3 to 3.5 % of the wind speed. In the northern hemisphere, in a direction 15 degrees to the right of the wind direction.

As a "back of the envelope" calculation, get wind and current speeds in the same unit (e.g. knots), use the current direction as the basis and compensate for the wind direction.