The nearest airport to Ischia Ponte is in Naples (Capodichino Airport). From there, you can take a taxi or a bus (ALIBUS express, fare 5 EUR) to the port in central Naples.
On ALIBUS buses, travel is free for children aged 0 to 6. Each child must be accompanied by an adult. If there are two children under 6 and only one adult, rules require two tickets (for the adult and one child). However, drivers often allow children to ride for free.
The 5 EUR ticket is valid for 90 minutes, and the ride to the port takes about 30 minutes. This same ticket can be used for the Naples metro, commuter trains, or other public transport.
From Naples, ferries (Traghetto, Ferry) and hydrofoils (Aliscafo) to the island depart from the Molo Beverello and Porto di Massa ports.
Additionally, ferries and hydrofoils to Ischia depart from the Mergellina and Pozzuoli ports. There is also ferry service to the islands of Procida and Capri.
The ferry schedule is available here.
The hydrofoil schedule can be found here.