From Tenerife/South you can also take the ferry to La Palma. The ferry port of Los Christianos is about a twenty-minute cab ride from Tenerife South Airport. The ferries usually leave from around 6 – 7 pm, so that you arrive on La Palma at around 9 – 10 pm. On La Palma, the ferry departs at around 6 a.m., so depending on the flight connection, you will need to plan a corresponding stay on Tenerife. Exact departure times can be found on the ferry companies’ websites. Fred Olsen offers a fast ferry that takes about 150 minutes from Tenerife to La Palma.
Ferry connections Fred Olsen:
https://compra.fredolsen.es/Booking/en/search