One of the gems of the Archipelago is the old Hjortø mail boat. With its characteristic hot-bulb engine from the Hundested engine plant, the boat delivered the mail to Hjortø from 1954 to 1976. Until 1969, the mail boat sailed alongside the Ærø ferry in the Højesteneløbet channel unloaded its passengers, brought new ones aboard plus the mail, and then sailed back. Several leisure sailors refrain from navigating Hjortø because of the depth. However, the conditions of the sea bed create a funnel leading to the dug-out fairway, which is one and a half metres deep and leads to the harbour – so, if you are careful, navigating Hjortø is definitely possible.