  The Widefield Arecibo Virgo Extragalactic Survey (WAVES) was an ongoing HI
survey of the Virgo Cluster with the Arecibo Observatory's 305m William E.
Gordon Telescope at the time of its structural failure. The full 20 square
degrees of the southern field and 10 of the planned 35 square degrees of the
northern field had been observed to full depth, adding to 25 square degrees
observed to the same depth in the cluster by the Arecibo Galaxy Environment
Survey. We here review what WAVES reveals about four optically dark HI
structures that were previously discovered in the survey area, including two
that are not seen despite being well above our detection limit.
