IPhO 2012: how magnets curve the water

An overview of the 43rd International Physics Olympiad (held in Tallinn and Tartu, Estonia) is given; this includes short summaries of the problems and competition results. Experimental problem no 1 is discussed in detail, including the full text, solution, and additional theoretical analysis. In this experiment, laser beam reflection from the water surface is used to calculate the recession depth of the water surface above a strong permanent magnet; this result is used to determine the magnetic permeability of the water.