There were three HSS craft operating out of British ports: Stena Discovery (Harwich-Hoek van Holland), Stena Voyager (Stranraer-Belfast) and Stena Explorer (Holyhead-Dún Laoghaire). The Discovery was withdrawn in 2007 and was sold to a ferry company in Venezuela (Ferrymar) during 2009, but has lain out of use since its arrival in the country. In May 2013 the Voyager was towed to Landskrona, Sweden for scrapping. It is likely that the Explorer will suffer the same fate as the Voyager as, given the crafts' appetite for fuel, it is unlikely that any other company would be willing to take over its operation. At the time of its withdrawl, a report noted that the Discovery's operation on the Harwich - Hoek van Holland route was using more fuel than Stena's seven other conventional ferries on the North Sea put together.
Noel, I doubt if the service's withdrawl will have a huge impact on the traders in Dún Laoghaire. With only one return trip a day day trip traffic from Wales must have been virtually eliminated and, in any case, the bulk of day trippers took the DART into Dublin city centre. Car and lorry traffic would have driven directly to / from the ferry terminal and would not have been a significant player in the economy of the town.