Code
Stair risers shall have a minimum uniform height of six inches (15.2 cm) and a maximum height of 12 inches (30.5 cm), with a tolerance of ½ inches (12.7 mm) between adjacent risers. Stairs shall not be used underwater to transition between two sections of pool of different depths.
Note: The bottom riser may vary due to potential cross slopes with the POOL floor; however, the bottom step riser may not exceed the maximum allowable height required by this section.