Lifeguard threshold

Definition

The pool size and headcount that put a guard on the deck, who may not teach while there.

Why It Matters

Class ratio is the unit economics and this is the second body the ratio never counts. Ohio's rule turns on square feet and swimmers together. Under two thousand square feet a pool needs no guard up to fifty bathers and one above that. At two thousand square feet the first guard is required even for a single swimmer, and a bigger pool at a busy hour needs three. The line that costs money is what a guard on duty may not do, and the rule says it plainly: not be engaged in swimmer instruction or coaching. So every guard hour is a lane hour earning nothing, and the pool sold as the growth story is a payroll step. A home-based school should read the other end of the same chapter, where a private pool stays private only while one instructor teaches with no more than four people in the water.