The primary way visitors come to Campobello Island is over the Franklin D. Roosevelt International Memorial Bridge. Until the bridge was built in 1962, a ferry was the only way to reach the island, unless you have a private boat.
The bridge spans "The Narrows," an area of swift and treacherous tidal currents. As you cross the bridge you will be treated to spectacular views of Passamaquoddy Bay.
Just across the bridge, going either direction, be prepared to pass through immigration and customs between Canada and the United States.
We had beautiful sunny weather for virtually our entire 3-days, so our two ferry rides between Deer and Campobello Islands were very enjoyable as well. A private company, East Coast Ferries Limited runs two ferries from the end of Deer Island that is furthest from the mainland. The one that we were interested in runs to and from Campobello Island every half-hour between 8:30 AM and 7:00 PM. That is, the ferry leaves Deer at 8:30 AM, it leaves Campobello at 9:00 AM, then Deer at 9:30 AM and so on. Their second ferry serves the nearby American town of Eastport - claiming to be the most easterly town in the United States. It makes a similar run between the hours of 9:00 AM and 7:30 PM. We paid C$4 (US$3.60) each for our bicycles (cash only), while a car/driver pays C$14 and C$3 per passenger to a maximum of C$20. Motorcycles cost C$7, motor coaches C$50 and large trucks/trailers are charged C$1 per foot.
This ferry had a slick arrangement whereby the powered tender 'Hopper II' is attached to the mid-point of the vehicle-barge by a long steel beam on a pivot. Once the ferry backs off the beach with its load, the 'Hopper II' releases one of its attachments to the barge and swings itself around in the other direction by means of this pivot (see the 3rd photo). Deer Island sailings are from the very picturesque Deer Island Point Park but the Campobello Island docking area is very ordinary and not very far from Friar's Bay (see the 3rd map in my 'General' tip). The ferry route also gives you a good look at the 2nd largest whirlpool in the world - the 'Old Sow' just off Deer Island Point and we were also lucky enough to spot a Minke whale surfacing on our return voyage!
Russ and I did not go crazy with biking on Campobello, since we were on the island for only 1 day. An easy ride to the historic Franklin D. Roosevelt cottage in the International Park was followed by about a 3.5 hour (including lunch) trip on the hilly Route 774 out to Head Harbour Light. Traffic was a bit heavier than on the less populated and harder to get to Deer Island, but it was still not all that bad and the sun was shining! We had some great views along the way, including this view of distant Atlantic Salmon pens, used for commercial farming of this species, at the entrance to Head Harbour. A lot of the traffic was due to the fact that we were biking along the road leading to Wilson's Beach, the largest community on the island (2nd photo shows the highway as it passes through). Although we had to deal with a few hills, they were not as bad as the ones we had to deal with along the eastern side of Deer Island on our return trip to the mainland the next day!
In the days that Franklin Roosevelt and his family spent time on Campobello Island, they would ferry across from Eastport, Maine. In the 1960's a bridge (FDR Memorial Bridge) was built from Lubec, ME and now makes the island very easy to get to. Eleanor Roosevelt was able to attend the dedication of the bridge not long before her death.