Esriâ??s ftp server were moved to a hosted secure ftp site. New login details are in this post from the ArcHydro forum:
http://forums.arcgis.com/threads/61799-ArcHydro-update-for-ArcGIS-10.1?p=255162&viewfull=1#post25516...
Youâ??ll want to use something other than your web browser to access and download.
Data for ArcHydro 2.0 Tutorial is in the /incoming/ArcHydro/Data/Tutorial directory
Tutorial for ArcHydro 2.0 (ArcGIS 10.0) is in /incoming/ArcHydro/Doc/ArcHydro2_0
Read the useful PDFs in /incoming/ArcHydro/Doc/ArcHydro10_1 (ArcGIS 10.1) and
/incoming/ArcHydro/Doc/ArcHydro2_1 (ArcGIS 10.0)
No specific tutorial or data for 2.1 or 10.1 (ArcGIS 10.1) but the 2.0 tutorials can be followed once data is brought in with ArcCatalog, some adjustments for changes in the newer ArcHydro builds.
Tutorials docs and example data for archydro 2.0 are free avaialble here