Sun shelf
Also called: tanning ledge, Baja shelf, tanning shelf, Baja bench.
A sun shelf, also called a tanning ledge or Baja shelf, is a shallow platform inside or beside the main pool, typically holding somewhere between 6 and 15 inches of water, meant for lounging rather than swimming. The three names describe the same feature.
Why it matters
On a concrete pool a sun shelf is poured with the shell, decided before gunite, and cannot be added later; a fiberglass pool gets the ledge moulded into its shell. The number that decides whether it works is published two ways: builders quote ledge depth, furniture makers quote water depth, and the water sits about three inches below the ledge. River Pools recommends a 9 to 12 inch ledge. That matters because six of the ten in-pool furniture pieces we track cap at 9 inches of water. Write the water depth on the plan. A shelf is also shallow, warm and bright, which is where algae and scale start. It needs an in-ground shell, so an above-ground pool cannot have one.
In numbers
A 12 in. ledge is 9 in. of water. Go to an 18 inch ledge and you have 15 inches of water, which excludes almost every standard in-pool lounger and chair.