def harmonize_ocean(ocean, elevation, ocean_level):
    """
    The goal of this function is to make the ocean floor less noisy.
    The underwater erosion should cause the ocean floor to be more uniform
    """

    shallow_sea = ocean_level * 0.85
    midpoint = shallow_sea / 2.0

    ocean_points = numpy.logical_and(elevation < shallow_sea, ocean)

    shallow_ocean = numpy.logical_and(elevation < midpoint, ocean_points)
    elevation[shallow_ocean] = midpoint - ((midpoint - elevation[shallow_ocean]) / 5.0)

    deep_ocean = numpy.logical_and(elevation > midpoint, ocean_points)
    elevation[deep_ocean] = midpoint + ((elevation[deep_ocean] - midpoint) / 5.0)