Here's a clue, they are both in the north country and were highlighted in a story in the Union Leader this weekend. 

TripAdvisor named Whale's Tale Water Park in Lincoln and Kahuna Laguna in Conway to their top 25 list of Best Waterparks in America. The awards are part of their Travelers Choice awards for this year.

The article lists features in both water parks that draw crowds to them and accomplishments both have achieved.  Both attractions are great day trip ideas that you can get to on just one tank of gas while there is still most of August yet to go.