This in from Wightlink, in their own words, Ed
Update 12.39: The mechanical difficulties that we were experiencing on our Portsmouth – Ryde catamaran have now been resolved and normal service has resumed.
Due to mechanical difficulties we have been forced to cancel the following sailings:
Portsmouth Harbour – Ryde 06:40
Ryde – Portsmouth Harbour 19:15
We’re sorry for the inconvenience this will cause, if you are concerned about your sailing please call us.