TMZ is reporting that they did some research (that's why I'm giving them some props, I'm too lazy to do research) and have found that all children under the age of 12 in Hawaii are required to wear a life jacket, but just when they're doing water stuff.
The Arquettes are in Hawaii. They are doing water stuff. Coco is under 12. I think David is right around there also. Courteney is about 45, so she's good. Please note the lack of PFD(s).
Photo: Ramey via TMZ