You know, this sounds like a really unsafe setup. Eight hours seems way too long to expect someone to remain energetic and attentive.
Who covers him for bathroom and lunch breaks? Does he have to close the pool?
(I am actually just curious now.)
He works 5 a.m. to 11 a.m., but his replacement is routinely up to 2 hours late, hence the 8 hours. Somehow that's not fireable, but since his shift is 6 hours, they don't need to give him a lunch break. If he needs a bathroom break, a member of the maintenance staff covers for him, usually at some point when the pool is empty.
So, our state has 2 different kinds of lifeguard jobs. One is the kind you see at Great Wolf Lodge, where someone is actively guarding, and then there are rules about how often you have to rotate them out, etc . . .
But the other is what I call a "pool babysitter". They check the pool chemicals, and stay in the pool area and are responsible for calling 911, and doing CPR, but they aren't technically watching the pool, so they don't need breaks etc . . . and someone CPR trained can cover for them.
At the pool at our building the "pool babysitter" reads most of the time, and apparently that's legal, but DS's company has decided it gives them a bad reputation if someone looks in the window and sees the lifeguard reading.
DS does watch the people swimming. It's the most exciting thing he has to do, beside mopping, but it's not quite the same as a lifeguard at a large public pool.