It is possible things have changed from Feb, but we didn't have a formal night, just a dress up night on the second night. This is when most families had their nice family photos taken. We were at Triton's that night and it is a little more formal restaurant. It was also late seating and there were less kids and more adults.
The first night was cruise casual. Most men were in khaki pants and polo shirt, women in all sorts from sundresses, pants to capris.
I didn't see shorts on any night, other than the third night which was pirate night and it was kids wearing their pirate gear.
The fourth night was cruise casual again.
At Palo for dinner is was shirts and ties or jackets for men. Nice dresses or slacks for women.
The Brunch was more casual, but definately no shorts.