On the first day of your trip to Hermana Mayor Island, start by taking a ferry from the mainland to the island. Once you arrive, check into your accommodation and get settled. The island is known for its pristine beaches and crystal-clear waters, so spend the day exploring the coastline. Take a leisurely walk along the sandy shores, go for a swim, or simply relax and soak up the sun. In the evening, enjoy a delicious seafood dinner at one of the local restaurants, where you can savor the island's fresh catch of the day.