The island is self-sufficient in electricity and has its own water supply which for centuries has come from rainwater collected in open wells. In recent years, however, the supply has been supplemented with drilled wells and water conveyed to the island from Bornholm. Everything on both islands is housed in buildings listed on the historic register, as the islands previously formed a large fortification.

The archipelago is also home to the Græsholmen bird sanctuary where Baltic “penguins” are found. In recent years, the seal population has rocketed on the westernmost skerry “Tat”, which now has so many 300-kg grey seals that if a newly arriving seal squeezes itself up onto the rock, this causes another seal to fall into the water. The harbour has two approaches, one on either side of the swing bridge, separating the harbour basin into south and north harbours.

Visiting yachters are welcome in both, but only a few berths are available in the north harbour. The harbour can be entered day and night and always one or other of the approaches will not have the wind against you. Strong winds blowing directly into the entrances create some turbulence in the harbour. If the harbour cannot be entered, a black sphere is raised and three red lights are switched on. The island’s unique atmosphere does not really start until the first 5 pm gathering at the inn, to celebrate that fact that all the “threehour tourists” have left the islands for the day. A visit to the islands in your own boat is an unforgettable experience.

Someone must have had yachters in mind when the this natural harbour was created between the two islands surrounded by 100-metre-deep waters, 10 nautical miles from Bornholm – reminiscent of Utklippan, located 10 nautical miles from Karlskrona, Sweden. And to top it off, the Ertholmene archipelago are the only islands between Bornholm and Karlskrona’s skerry-filled coastal waters.