Kos is the main harbor on the island. It is a large and safe harbor although it is subject to N-NE winds which can cause considerable swell within the large harbor. As an alternative a yacht can go the near by Kos Marina.

In the last few years the harbor has been changed due to new extensions. Now yachts can moor on either the E side of the harbor under the castle or on the NE side, outside the harbor, when the weather is settled.

The S side where yachts used to anchor is now reserved for the many day-trip caïques. Go wherever there is room. Expect the harbor to be crowded during the summer months. Anchor in about 5 m depths and go stern-to to the quay. Excellent holding on mud.

The quay under the castle now has water and electricity outlets, although these are only available during peak season (July - September) when the quay is manned and a charge is made.

Outside those months mooring is free but there are no facilities. Many supplies can be obtained in the town, but due to the extremely large number of tourists the town has lost its soul.