Originally posted by tjkraz
The PLUS feature represents one VISIT to Blizzard Beach, Typhoon Lagoon (water parks) or Pleasure Island. You can say all day with the one visit if you wish, but you cannot leave the park and return in the same day.
Note that this Plus visit does NOT use one of your 4 park hopping days if you choose not to enter one of the main 4 theme parks on that day. In other words, you can actually get 5 full days of entertainment from a 4 day PHP if you visit the main parks for 4 days and a water park on a separate day.