(1) The water depth shall be plainly marked in units of feet and inches at or above the water surface on the vertical pool wall and on the flat edge of the deck or walk next to the pool.
(2) The water depth shall be marked at maximum and minimum points and at the points of break between the deep and the shallow areas. The markings shall be paced at no more than 25 feet intervals measured peripherally.
(3) Depth markers shall be in numbers of at least four inches in height and in a color contrasting with the background.
(4) Where depth markers cannot be placed on the vertical walls above the water level, other means shall be used to plainly mark depth levels in a manner to make them plainly visible to persons in the pool.
(5) The depth in diving areas shall be marked.
(6) Lap pools shall have depth markers spaced at not more than 25 foot intervals and at each end of the pool.