Ferry from Ios to Milos (Adamas).

Ios and Milos sit on opposite sides of the southern Cyclades, and the ferry between them is how many island-hoppers swap the central islands for the western ones. Ios is known for the beach at Mylopotas, the bars of Chora and a surprisingly wild interior; Milos for its volcanic coastline, pale rock formations and boat trips to coves you cannot reach by road. About 36 nautical miles of open sea separate the two harbours.

This is not a busy shuttle. Ferryhopper lists sailings on 2 to 7 days a week, and in its table of last year's sailings, Blue Star Ferries and Fast Ferries each sailed this way only once or twice a week, all year round. Seajets fills the gaps in summer, from May to September, but in the rest of the year you are on the conventional ships or not travelling at all.

Price and speed do not line up the way you might expect. The Seajets boat takes about 2 hr 50 min and starts at €93.70. Blue Star took as little as 2 hr 45 min in May and June of last year's table, though about 4 hr 5 min in other months, and costs from €11.50 to €21.50. Fast Ferries, from €14.50, takes about three and a half hours.

Timings deserve attention too. On our sample day, the Fast Ferries ship left Ios at 21:00 and reached Milos at 00:30, so book a room in Adamas and a pick-up before you choose the cheap late boat. Whatever you take, book this leg first and build the rest of your trip around it.

Heading west from Ios, the ferry crosses a stretch of open Aegean with no shelter from the north. In July and August the meltemi can build a real swell here, and the Seajets high-speed boat is the service most likely to be delayed or kept in port by the coast guard. The conventional ships are more resilient but sail only once or twice a week each, so if one is cancelled, the next option may be days away. Operators will rebook or refund you. Keep your plans loose around this leg, and never pair it with a same-day flight from Milos.