The dream of a cycle route along the South Coast is close to fruition.
This mammoth near-400 mile undertaking from Dover to Devon pieces together paths and promenades, sometimes just metres from the sea, sometimes heading inland to dodge the traffic. With a little resourcefulness to navigate the few remaining missing sections, you can now follow route 2 almost all the way to Plymouth.
East of Dorchester/Weymouth it's largely level; west from there, the Jurassic Coast and the foothills of Dartmoor give you more of a workout.
Don't expect to make continual fast progress - the seafronts are often busy with pedestrians, and in a few urban areas you'll need to keep your eyes peeled for signs as the route twists and turns. There are countless possibilities for day rides, but this would also make a grand holiday of a week (or more) for the cycle tourist.