Method for measuring a rheological transition level between a first layer with first rheological properties, typically a fluid mud layer, and a second layer lying thereunder and having different, second rheological properties, typically a solid mud layer, wherein using a cable an object is lowered through the first layer into the second layer lying thereunder. A dynamic quantity of the moving cable with object, influenced by the rheological properties, or a change of this quantity, is measured. It is determined on the basis of this measurement when the object is located at the rheological transition level.