- The best time to visit is two hours before high tide and during ocean storms
- Stay on the platforms and behind the protective rails
- Obey the posted Park sign that closes the lower platforms during dangerous weather
- The ledges are often slippery and prone to rogue waves
- Watch young children around the high cliffs and uneven ledges
Timing is essential if you’re looking for that exciting splash. Famous photographs show 40 foot sprays and the talk is of booming sounds of thunder, thrilling those who have witnessed it, but Thunder hole also has an ominous history of rogue waves.
Thunder Hole is a narrow channel of solid granite. When the waves come in strong and quick, air becomes trapped in a cavern that is higher than the inlet. When enough force pushes the waves into the cavern the air escapes with a thunderous reverberation. The relationship between ocean and rock is always changing. As time has passed, the cavern has been carved out by the waves, resulting in less reverberation.
Location and Services
Thunder hole is two miles from Sand Beach. The channel view is accessed by concrete stairs and a handicap accessible ramp with protective railings. This is the safest area in which to view the waves during ocean storms. It is recommended that you do not leave the walkway onto the ledges during rough weather. The ledges are often wet and slippery and the granite rock uneven and unforgiving. People have been knocked off the ledges into the ocean here.
Thunder Hole also offers a lovely little gift shop and information center. This gift shop was the first ranger station in Acadia National Park. The Island Explorer free bus service stops here frequently during the summer months. The Thunder Hole Restrooms are also located in the parking area.
If you’re going for the photographic opportunity, be prepared to wait for the right weather, the proper tide, and patient observation. If you’re expecting the 40 foot wave often seen in pictures you may be disappointed. The peak time is two hours before high tide or during ocean storms when the waves are found at their best. Bring a picknick basket and have lunch on the granite ledges in good weather or walk the ocean path, visit nearby Otter cliffs, sand beach or the numerous trails. Thunder Hole is a nice distraction when your planning a full day of nearby park activities.