If the surf is small or you are just looking for an easy adventure, traveling to Ometepe Island for the day is a great option.  Ferries are available out of San Jorge (about 45 minutes from Hacienda Iguana) which can get you to the island in 1 hour.  Once there, you can hike to a waterfall, ride ATVs around the island, enjoy the natural springs at Ojo de Agua, or just enjoy the view of both volcanoes.