"PLATES,ALUM QQ-A-250/19,SHAPES,ALUM QQ-A-200/50; CROSS SECTION IS U-SHAPED FROM 3 INCH DEEP TO 1 FT 9 IN DEEP; WIDTH IS 5 IN AT THE TOP TO 3 IN AT THE BOTTOM; TAPERING 5 DEG ANGLE; BOTTOM OF SKEG IS 3 IN WIDE BY 1 IN DEEP MADE OF CHANNEL ALUM,OVERALL LENGTH IS 25 FT"