Thank you for your inquiry.
The requested Seasat data are retired, but are available via ftp.
(they are the really old binary format
We are hoping to have them converted into netcdf and available online this summer, along with documentation and read software.
PO.DAAC Legacy Retired Products:https://podaac.jpl.nasa.gov/PO.DAACLegacyProductshttps://podaac-www.jpl.nasa.gov/products_retired