CANOEIST MAGAZINE REVIEW
The following article written by Peter Knight and published in the June 1990 issue of Canoeist magazine gives an independent view of the paddling to be found on the weir.
It is reproduced here by kind permission of Stuart Fisher.
PLAYHOLES - HAMBLEDEN WEIR.
The Thames weirs are the subject of an ongoing love hate relationship with the majority of white water paddlers who have sampled them, they are admired for their standing waves, offering superb surfing and excellent looping potential, and also because they possess moving water of some description almost all year round owing to the volume of the River Thames.
On the other hand, they are also home to some ferocious whirlpools and boils that are the despair of many paddlers. It is important to remember that any weir, being a man-made structure, will not exactly mimic the water formations associated with a natural river but will rather generate unique (and interesting) features of its own. These should be accepted and utilised not moaned about!
The weir at Hambleden is a good example of a white water play site which deserves some attention from both squirtists and float boaters. As with many of the Thames weirs Hambleden consists of a huge sloping low header dam, bypassed on the river right hand side by a lock for the passage of larger craft. The dam itself is pierced by a number of single radial sluice gates and a main set of sluice gates in the center of the dam.
Depending on the river level and the vagaries of the authorities, some or all of these gates will be open, creating tongues of white water in the weir pool below. We visited Hambleden on a day early in April when 3 of the 6 gates on the main sluice were open, together with one of the radial sluices, a fairly normal configuration. The water level was low with only a slight trickle running down the face of the sluice.
The main focus of interest is of course the main sluice itself, Hambleden rarely fails to provide a good surfing wave at the top of the main shoot and this occasion was no exception. With only 3 gates open the wave is not particularly big or well formed and prolonged rides required a high level of body English To stay on the face, leaning back and forward to balance the boat and prevent a slide backwards off the wave. For that reason it is a great place to hone surfing skills.
Looping in float boats proved unusually elusive at this water level, probably because the wave face was not very steep and because it was hard to find a surfing position stable enough to be able to bury the bows in a controlled manner. On the other hand, the diagonal stopper forming on the top wave did add interest, allowing a side surf whilst pointing almost upstream.
The setting (and the surfing) can he pretty daunting; there is a sharp differential between the deceptively slow eddy and the current created by tons of water hissing through the sluice gates. Any approach must be both intentional and aggressive.
Once on the face of the ware, vision is restricted to the massive, rusty ironwork of the sluices hovering in front of you. The only barrier preventing a 4ft head of water crashing into you.
In flood conditions the main wave train can extend to 50 yards downstream with well formed waves along the whole length and in these circumstances Hambleden has some of the biggest and fastest waves to he found in England. However, on the day we visited, the water was medium to low and the wave train was rather confused and unpredictable below the first wave. The second wave was a surging haystack, periodically collapsing in a welter of foam which rather destroyed its surfing potential.
It can function as a launch pad for squirt boats aiming to rocket move off its crest, having first peeled in at the top of the eddy.
On the river right of the wave just off The eddy line, there is a whirlpool that forms then moves downstream as a sort of surging boil.
Many of the squirtists present felt that this had potential but for what none of us were brave enough to find out. However, I would speculate from the safety of my armchair that some pretty amazing mystery moves could be performed in this whirlpool..
The eddy line on both sides of the main shoot provides the squirtist with some fine opportunities for cartwheels, screw-ups and bow and stern squirts and indeed is long enough to allow sequences at these moves to be strung together. For float boats, the eddies fulfill their traditional role as resting/queuing places.
The side radial was a typical weir-type water formation, very boily but fairly flat. For float boats the fun consists chiefly of carving across the current and hitting the eddy turns on each side; this is a good place to learn the rudiments of carving since the eddies are strong and there is plenty of space in which to make your mistakes. For squirt boats, the eddy line was sufficiently good to allow sequences of cartwheels, screw-ups and pivots to be strung together without the fear of being carried over the next drop, as can happen on a natural river. Great care should be taken to avoid the stopper that forms between the vertical concrete walls of the radial itself; this is a very dangerous place, being both very shallow and having no exit. It is possible to enter this stopper from downstream so be very careful near the top of the shoot.
The Squirt boaters derived a lot of fun and spent a lot of time at the point at which the current from the side radial meets the current from the main sluice at right angles. This point is well below the main sluice so no real waves are around but a very odd boil is created with a seam line through its centre. This was good squirt country with lots or potential for immersion mystery moves and a number of static points for vertical transition moves, cartwheels and the like. Whilst no rocks exist to be splatted on any of the Thames weirs somebody has thoughtfully provided big splatting posts (actually for hanging slalom gates) in the heart of the river right eddy on the main sluice. There are also plenty of walls, including the weir sill itself, to practice vertical parking against.
Hambleden proved to be a good site for play boating, provided an enquiring mind is applied to the unusual water conditions. It is well worth a visit, particularly in the winter when it is more likely to be in spate and generating a wave train that matches any in England.
There are, of course other weirs on the Thames that are equally worth visiting but bear in mind that any canoe launched on the River Thames requires a river license. obtainable from the lock keeper. It is also courteous to contact the local club (Chalfont Park in this case) to enquire about water conditions, car parking, access, etc. It is essential at all times to pay due care and attention to safety considerations. All play boating moves should have pre-planned safe exits before the moves are attempted particularly if they involve maneuvering close to any obstacles that may trap a boat. All equipment used should be appropriate for the prevailing water conditions.