Wait till he is off duty

You could use your powers to manipulate him, but you'd rather wait for this one out. You sit on the side of the pool, casually teasing yourself in the shade, formulating your plan of attack. Before you not too long it gets darker and the lifeguard blows the whistle, signaling everyone to leave the pool. Once the pool was empty, he closes the umbrella and starts walking down the ladder. You make eye contact.

"Pool's closing, time for you to go." He says in a gruff and indifferent tone,

"Not quite, you're giving me night swim classes. Don't you remember," you say? The man's eyes fog momentarily.

"I... I don't know why I agreed to that. No one is allowed to swim in the pool after..."

"I bet you don't give a fuck about the rules," you smile, "Just a quick lesson please, I'm useless."

"Well, alright," he says, "Let me lock up and we can begin. He leaves, but after a few minutes return, "Alright, we only have a little bit before it gets too dark. I can't turn the lights on because they are on a timer, so let's make do." You nod and you both jump into the pool. "Okay let's start. My name is Matt by the way. How familiar are you with swimming?"

"Not very," you lie, "I sink like a brick,"

"Okay then, let's start with that," he says, "try floating."

"How do I do that?"

"Lay on your back." he says, and you do. He then proceeds to stick his hands out placing them to support your back.