Looking for a water safety flotation device thingy

 We're going camping for a week and there is a lake and apparently a pool where we are going and we have nothing to put on Hudson to keep him safe. I was thinking of like a life jacket/safety vest with those water wing things or something, I'm really not up to date on what's available and was wondering if anyone had anything they could let me borrow. We will be with him and holding him at all times in the water, my wife just wants extra security. He wears a 3T. If nobody has anything to loan, if you could point me in the right direction to the cool flotation device to use I would appreciate it.

Thanks,

Charette