Nelly Bay is where the ferry arrives, and it functions as the island's commercial hub — such as it is. The small marina here is the most protected anchorage on the island, and you'll often find yachts moored here overnight. The beach at Nelly Bay is pleasant for swimming and has a stinger net during jellyfish season.
The main street of Nelly Bay has a supermarket, the island's ATM, most accommodation options, and a handful of restaurants and cafes. If you're spending more than a day on the island, stocking up here before heading to your accommodation elsewhere makes sense. The ferry terminal is on the northern edge of the bay; buses to Arcadia and Horseshoe Bay depart from just outside.