Despite having a paid/confirmed reservation on Dockwa, and exchanging messages with with the SYC manager confirming same -- we were not provided with a slip number prior to our visit. The afternoon of our arrival, we called ahead to request a slip number -- and that went to voicemail. Our call was not returned. We arrived later that night to find a completely full marina, and no place to park our boat. Singapore YC had every opportunity to provide us a slip number via email, text or voice call. This situation could have been avoided - easily. But their lack of follow-through put us in a vulnerable and frustrating position. It is hard to fully express our level of frustration with polite words.