PURPOSE: To make the leveling operation of rubble slope under water easier by a method in which many downwardly directed blades are provided in parallel to the front edge of a frame of triangular cross section, and plural rollers are provided by arranging them in the sloped direction to the rear.

CONSTITUTION: Many downwardly directed blades 2 are provided in parallel to the downside of the front edge of a frame 1 of triangular cross section, and plural rollers 3 are provided to the rear to obtain a leveler A for rubble slope under water. A rope 17 from a ship S is attached to the frame 1 and lowered to the upside of the slope of rubble B under water. The ship S is moved to the direction of arrows and the rope 17 is paid out in order. Whereupon, the leveler A moves along a design line C. The rubble B can thus be leveled off by the blades 2 and compacted by the rollers 3.