Floating Dock Lifting Ladders Lifting ladder for floating docks with sliding rung section that stores upright completely out of the water. All welded construction from 1-1/4" I.D. marine grade 6063 T-5 aluminum to resist corrosion. Serrated rungs provide a non-skid surface rung with no sharp edges. Distance from dock to bottom rung: 13" retracted, 5' extended. Rated for 665 lbs. per rung.