1. Aqua Socks: They call this the rocky coast for a reason. If you want to explore at low tide, you'll need sole protection.
2. Slickers: Morning fog and evening showers make coastal Maine dramatic―and wet. Bring a raincoat, and be prepared.
3. Sunglasses: When those showers pass, you'll want to enjoy spectacular views.
4. Binoculars: Maine boasts an incredible diversity of plants and animals―many of which are best enjoyed from afar. (Black bears, for example.)
5. Sunscreen: The mean temperature may be 49 in Portland and Bangor, but reflected rays from the sun are still powerful. Cover up.
6. Insect Repellent: Everything you've heard about local black flies and mosquitoes is true. Mainers recommend Ben's 100 Insect Repellent, effective for up to 10 hours.
7. A Sweater: See #5 above for mean May temperature!
8. Delorme's Maine Gazetteer: A fabulously detailed atlas (produced by a local company), that shows every back road you'll want to explore. Visit delorme.com.
9. Easy Listening: CDs from Maine pianist and composer Paul Sullivan. Visit rivermusic.com.
10. Required Reading: Essays of E.B. White, who lived near Blue Hill and wrote lovingly about the state for more than 40 years. Visit bluehillbooks.com.