1 Park at Brookwood Station, and catch the train to Ash Vale. Drop down the steps out of the station, and turn left up Station Approach. Almost at the end of the road you'll see the canal, down a short concrete ramp on your right. Walk down to the tow path, turn left under the railway bridge, and continue with the canal on your right-hand side.
2 At first, you'll be walking beside the backs of the houses in Ash Vale; then the railway draws alongside, and soon you'll see the canal centre at Mytchett, just across a little swing bridge. Beyond the canal centre you enter the wooded section running almost unbroken to Brookwood. You'll pass Frimley Lodge Park, where enthusiasts operate a miniature railway on Sundays and Bank Holidays.
3 The tow path changes sides at the Guildford Road bridge which, like several of the bridges along the canal, has been painstakingly reconstructed to the original design. Just beyond the bridge, you'll cross the aqueduct over the main London-to-Southampton railway; it was built in 1838, and extended when the railway was widened in about 1900.
4 Next comes the high concrete bridge at Deepcut, heralding the ½ mile (800m) cutting that gives the area its name. It leads you to Frimley Lock, and the start of the sinuous 14-lock flight that leads the canal down to Brookwood. This is a lovely section, shaded by young oak trees, and the locks themselves blend into the landscape like ornamental temples in some stately pleasure ground.
5 Just past the pink cottage at Pirbright Lock the tow path changes sides again, and you zig-zag left and right across Pirbright Bridge. Continue for a further 850yds (778m), until you reach a green lattice girder bridge. Cross the canal here, signposted towards Brookwood, and walk up Sheets Heath Lane to the station where your walk began.