In reply to eddzzz: You will not find many DWS routes at Severe, the Torbay area (already mentioned) which features a number of long traverses is your best bet, be warned though that a Sport grade of 4+ is more like VS than S in Trad money. Generally rock has to be vertical or overhanging for DWS to be safe, so grades tend to be higher than Severe - you do not want to be hitting ledges if you fall off.
Aside from Torbay you will find some good starter DWS routes on Aquanaut Buttress at Swanage, several of these are probably around HS in standard, although like most DWS they are given Sport Grades. An abseil is required to gain access a good ledge above the climbs.
http://www.ukclimbing.com/logbook/crag.php?id=8231
Temporary Lifestyle situated East of the Lighthouse at Portland is another relatively amenable classic at HS,
http://www.ukclimbing.com/logbook/c.php?i=13911
the Red Crane Traverse nearby is technically a little harder, but less intimidating as you are never high above the drink.
http://www.ukclimbing.com/logbook/c.php?i=13887