I would recommend May.
August is during hurricane season so there is a slight chance of missing a Port-of-Call or stormy weather. There is more rainfall in the Bahamas in August. May brings an average of 5 inches of rain but August’s average rainfall is nearly 7 inches.
The average high temperature in May is 84 while August is 89.
In addition, I looked at some pricing trends and May is generally priced a little lower than August. Any time kids are out of school, prices are likelier to be higher.
The
activities in the Oceaneer Club are listed in the Personal Navigator. Your family will receive this handy informational sheet upon boarding. It will list the activities for your first evening. Then, each evening on board, the Disney Wonder you’ll find the Personal Navigator waiting in your stateroom listing the next day’s activities. I love to return from dinner, find our bed turned down and the Personal Navigator beckoning me to plan our next day. Extra copies are always available at Guest Services as well.
To see an example of past Personal Navigators, search “Disney cruise personal navigator” in your web browser.