Ischia is 33km off the coast and ferries run year-round. Unlike Capri, Ischia has thermal spas, volcanic craters, and beaches that don't charge โฌ50 for a sunbed.
From Molo Beverello to Ischia Porto or Casamicciola. Alilauro and Medmar. Fast, frequent, no cars.
From Porta di Massa or Pozzuoli. Medmar and Caremar. Cars allowed. Pozzuoli ferry often cheapest and least crowded.
Hydrofoil from Molo Beverello for day trips. Slow ferry from Porta di Massa if bringing a car.