A nice easy flight if you're worried about getting lost is along the coast past Lyme Regis, then along the apparently world Herritage Jurrasic Coast past Portland and Weymouth to Swanage and around the Isle Of Wight. You can either stop at Bembridge for a cup of tea if you feel the urge (no PPR required as far as I recall) or, continue east right the way along the coast or turn around and head back. There are two Danger Areas D026 / D031 at Lulworth and just before Swanage, but you can call Plymouth Ops on the phone before you go to check the status of them. If they are inactive, just buzz right through.
There is some beautiful coastline along there, the water looks almost tropical from the air.