The Phantom of Nantucket: Nancy Drew Diaries, Book 7

Dear Diary...

I thought a trip to Nantucket with Bess and George would be a simple vacation, but of course mysteries seem to follow me everywhere! We're on this fun, end-of-summer trip because our friend Jenna has an awesome exhibit opening at the local Nantucket Nautical Museum and we wanted to support her. She was really excited about it until some creep vandalized her welcome banner.
 Now it's become clear that someone is out to sabotage the whole exhibit. I really need to find the culprit to help Jenna and to return some of the priceless artifacts that have gone missing from the museum. I'm pretty sure this is one beach vacation that won't be just fun in the sun.