The port of Ágios Konstantínos is artificial and located on the western side of its homonymous bay, 2.5 miles southeast of cape Knimís. The main quay, which is located in front of the settlement of Ágios Konstantínos is positioned vertically (from north to south) and its total length is 140 meters.

There are Ro-Ro ramps at the north and south ends of the quay, which are used for the landing of ferryboats. The depths close to the quay vary between 6.6 and 6.9 meters, except for a small part at its southern end, where the depths are 4.6 meters.

There is a mole at the southern limit of the quay, which extends to the southeast for 100 meters. The outer side of the mole is quayed with depths between 4.7 and 5.3 meters lying nearby. The 10-meter contour is located 25 meters from the mole.

A small basin, used by local fishing boats, is formed south of the pier. Its entrance is facing southeast and its width is 27 meters. However, as we move inwards, the width decreases, reaching approximately 20 meters in its northern part.