Its interesting that according to a fragment of the Cypria,Achilles marries Deidamia on Skyros **after** he sails to Troy.

According to a fragment of Cypria mentioned by Proclus,the Greek fleet is scattered from the wind.Achilles is driven off to Skyros where he marries Deidamia.Source :

All the leaders then meet together at Aulis and sacrifice. The incident of the serpent and the sparrows (2) takes place before them, and Calchas foretells what is going to befall. After this, they put out to sea, and reach Teuthrania and sack it, taking it for Ilium. Telephus comes out to the rescue and kills Thersander and son of Polyneices, and is himself wounded by Achilles. As they put out from Mysia a storm comes on them and scatters them, and Achilles first puts in at Scyros and married Deidameia, the daughter of Lycomedes, and then heals Telephus, who had been led by an oracle to go to Argos, so that he might be their guide on the voyage to Ilium.