When my family stayed at SSR last week, you did not need to wear masks laying in the lounge chairs. We wore them getting to our chairs and took them off once in the chairs. They had dedicated cast members going around cleaning the whole time. Once you were done at the pool, they asked to have the back of the chairs pushed up so they knew you were done and they could be cleaned.
Honestly, it was great. The slide was open and they have everything marked for social distancing when waiting in line for it.