Length: 15½ km (9.6 miles), or 18¼ km (11.3 miles) if you finish at Yalding. Toughness: 3/10
09:59 Dover Priory train from Charing Cross (Waterloo East 10:02, London Bridge 10:08, Sevenoaks 10:32), changing at Paddock Wood (arr 10:47, dep 11:00) for the Strood train which arrives Wateringbury at 11:11. Buy a return to Wateringbury.
Trains back are at xx:09 & xx:39 from Wateringbury and xx:12 & xx:42 from Yalding, again changing at Paddock Wood.
There are plenty of orchards along the Medway Valley and this should be a good time for apple blossom. There will also be some patches of ramsons (wild garlic) on the riverside stretches, and I remember a large field of pale blue linseed flowers on the extension to Yalding (although it might be too early for those).
The walk document lists a lot of options but to simplify matters I suggest sticking to Option a, the Main Walk with an extra loop out to the Horseshoes Inn on Dean Street, which you should reach at around 12.45–1pm. If that doesn't appeal there's an earlier lunch pub (the Good Intent) on Farleigh Green and two later ones in East Farleigh.
After your exertions tea'n'cake should be available at the Ramblers Rest Café, just across the river from Wateringbury station. And if that revives you an optional riverside extension to the next station on the line (Yalding) should help you burn off the extra calories.
You'll need to bring the directions from the L=swc.336.a page. If you're printing them off from the web page (ie. not the pdf download) you can save several sheets of paper by clicking Option a first.