Combine boating with fishing
Some nice places for underwater fishing are the bay of Koutalas on the southwestern coast of the island and the cape of Spathi in the south. Equally interesting fishing spots are the beach of Avessalos and Vous islet , south of Serifos, an ideal spot both for spear fishing and regular fishing. You can always ask the locals, who will be glad to inform you on the best fisheries and on any possible dangers of boating around Serifos.
In Serifos there is a diving school, where the instructors will introduce you to the countless secrets of the seabed around Serifos and they will help you to get to know the beauty of the underwater world. www.serifosscubadivers.gr