From around May to October, excursion boats make half- and full-day trips around the island (€18 to €25), usually taking in Kastro, Lalaria Beach, Trypia Petra (Punctured Rock) and the two spilies (caves) of Skotini (Dark Cave) and Galazia (Blue Cave), plus a swim stop; many continue to Skopelos and, in some cases, Alonnisos. Check the individual boat signboards at the old port.
Boats for private day trips are moored along the town's new port.
Diving & Snorkelling
The small islets off Skiathos' south shore make for great diving and snorkelling. Local dive schools offer beginner introductory dives (€60), Open Water courses (€400) and dive trips for those already certified (€50), as well as snorkelling trips (from €20). Reputable local dive schools include Koukounaries-based Skiathos Diving Center, Dolphin Diving (5.5km southwest of Skiathos Town) and Theofanis and Eva of PADI-affiliated Octopus Diving Centre in Skiathos Town.
Hiking on Skiathos gets you to places most visitors never reach. At the time of writing, 25 routes have been mapped, numbered and signposted. Long-time local resident Ortwin Widmann, whose excellent Skiathos: Hiking in the Aeagean Paradise (available at local shops) outlines all walks, offers guided hikes (€18 per person) in May, June, September and October.
A particularly popular hike is the demanding 12km, four-hour loop (Route 18) from Moni Evangelistrias to Cape Kastro, returning via Agios Apostolis.