Same thing once on Wonder with another O class ship in. We always walk onto the island early, do our walk around the area, grab a couple Coco Locos at South Beach, then an early lunch when they first open at Chill Grill.
When two big ships are in...those picnic tables fill up quick. South Beach bar way less busy than the others, especially early like that. We are headed back to the ship by 1 pm when it gets nuts.