Abstract: The present invention relater to a system of detachable and adjustable wave-breakers composed of rubber mattresses (1) filled with sea water on site and covered by vinyl tarpaulins (5), forming submerged wave-breakers the break sea waves uniformly, in a suitable manner for the practice of surfing and similar sports. The vinyl tarpaulins (5) that form the lateral, slanted faces of the wave-breakers are tied and retained by cables (3, 4) and anchors (2) suitably arranged on the ground underwater. In order to obtain the best slant relative to the direction of the waves each day, these “water mattresses” can be appropriately rotated about the vertical axis thereof, and the volume of these mattresses can be increased or reduced to adapt them to the momentary height of the waves and tides.