While you are in the town of Samana, do try to walk out to Cayo Vigía. My husband and I did, and we were happy we did. We think you'll be glad you did also.
The walk provides numerous photo opportunities with views of Samana City, the port, the bay, Cayacoa Beach (public swim beach shared with hotel), and lush forests. You might also be able to take a swim here, though we did not. And oh yes, there is a geo-cache out there as well. There is no restrooms out on the island nor obviously on the bridge walk. The closest restroom is at the public beach.
The walk is not for the mobility impaired, nor stroller friendly. There are steep stone steps both on what I will call the hotel end, and on the cay itself.
How to get there: from then tender pier in town, you could walk about a mile or so along the waterfront to the start of the bridge (Brug Samana van Leona) Cayacoa Beach in front of the Hotel Bahia Principe Cayacoa. From the beach, it is about a half-mile walk.
If you are pressed for time, you could take a local taxi to the base. That is another adventure we did, on paved road and dirt road. The taxi was an open--sided cart seating four, pulled by a motorcycle. A more conventional taxi could take you to the hotel, then you could make your way to the bridge.
You actually cross two bridges, with one span being longer. Some of the path is through a small but beautiful forest, part is on stone steps. The bridge is very sturdy with fine sturdy railings on both sides.
I am sure most people see the island, and the bridge from a distance, but do not make the small effort needed to get there.