I think that the answer to your question is , "badly". As far as I can remember there is a regular cargo boat (frequency not known) from Guernsey, an infrequent small car ferry to France & a small launch from Guernsey run by a company called "Bumblebee". Otherwise, it's just Aurigny - which was actually set up in1968 solely to replace the air links provided by Jersey Airlines - when they got rid of their Herons. Overall, AUR have provided quite a good service to Alderney ever since ( considering that less than 2000 people live there). However, there are many in Alderney who would not agree with me !