This section is 14.3 miles (22.3km) long - a map of it can be downloaded below.
Marlow is arguably set in the most beautiful stretch of the Thames Valley with the wooded slopes of Winter Hill rising on the opposite bank as you leave the town. Beyond Maidenhead the river becomes busier and in places there are views of grand homes finishing with the grandest of them all, Windsor Castle, towering above the water.
From Bourne End your route to Cookham goes through Cock Marsh, now managed by the National Trust but grazed as common land since 1272. Cookham is famous as the home of artist Stanley Spencer who lived here for 49 years and where the chapel is now a memorial gallery to his work.
Between Cookham and Boulter's Lock the beechwoods rise steeply on the opposite bank. This is the Cliveden Estate, which can be magnificent in November when the autumn colours are at their best, and notorious for the 1960s Profumo scandal. The National Trust now manages the gardens and woodland and the house is an exclusive hotel.