Ferry from Piraeus or Samos

There are daily boat excursions from Mykonos except Monday, because the archaeological site is closed that day.

Ferries to Hvar Island, mostly from Split

From Niigata to Sado Island, by jetfoil (1h) or car ferry (2.5h).

Transportation is limited to the Ogasawara Kaiun ferry, the Ogasawara Maru, departing from Takeshiba, Tokyo to Chichijima. The ferry runs every three days in each direction and takes 24 hours one way in good weather, but longer if the sea is rough (and it often is). (wikivoyage)

15 mins from Helsinki by ferry

You get there on a boat tour; several operators in the towns of Royan, Le Verdon-sur-mer and Meschers-sur-Gironde have scheduled departures in April-October.

Day trips sail from Skye and the Western Isles. You have to make yourself available for a two-day slot, and they sail on the first suitable day of that slot. It's a 3- to 4-hour crossing. (wikivoyage)

The ferry ride from Battery Park to Liberty Island takes just 15 minutes.

Portmagee is the usual departure point, for a 45-min crossing. (wikivoyage)

Two ferry companies operate regular passenger services to Mount Athos from Ouranoupoli.
See en.wikivoyage.org

Ferries open to visitors arrive in Gulangyu at either of two harbors: the more popular 1 Sanqiutian ferry terminal in the east and the slightly more out-of-the-way 2 Neicuo'ao ferry terminal in the west. (wikivoyage)

boat tours from Labuan Bajo (2-3h)

10min ferry from mainland to Miyajima Island
See jr-miyajimaferry.co.jp

There are frequent car ferries and much quicker hydrofoils from Milazzo and Messina on Sicily, and from Reggio di Calabria on the mainland, to and between the islands. (wikivoyage)

Ferry from the Gateway of India (1h)

"It is about an hour long boat ride from the coastal town of Santa Catalina or two hours from the fishing village of Boca Chica, but most travelers rely on tour operators to reach the island." (wikivoyage)

Pedestrian ferry between Brønnøysund and Rørøy dock on Vega Island, or car ferry from Sandnessjøen.

Ferries can be taken from the terminal north of Place de l'Independence. The trip takes 10-20 minutes.