The Erected Sail
Scholars have said that seeing a sail erected for the dreamer indicates attaining glory and honor. They interpreted curtains or veils generally as worries, with their meaning varying according to their location, color, and condition, potentially referring to concerns related to women, livelihood, religion, or worldly matters. A curtain, in general, may also signify security for the fearful and the hidden.
Per Ibn Sirin's Muntakhab al-Kalam fi Tafsir al-Ahlam
Note: These are traditional scholarly interpretations (ijtihad) drawn from a specific classical source — not a binding religious ruling, fortune-telling, or a prediction of the future.