The Boat Race course is just one small part of the Tideway - the tidal stretch of the Thames that reaches down from Teddington Lock through central London to the open sea. For hundreds of years the Tideway has been the venue for great rowing events, including Dogett’s Coat and Badge, the oldest sculling race in the world, while the Championship Course between Putney and Mortlake has been home to the Boat race every year since 1845.

The tides that mark this stretch of the Thames mean that the line of the fastest stream varies according to the level of water in the river, as well as wind and weather. The bends in the river mean that different parts of the course are exposed to winds from different directions which adds further mystery to the unpredictable conditions. The race is generally held on the incoming ‘flood’ tide, one hour before high water at Putney. This means the crews will race against the stream, but with the flow of the tide, and the cox of each crew will spend many hours working with professional Thames watermen, past coxes and specialist coxing coaches to learn where their best course may lie on Race Day.

The Boat Race course is marked by three classic bends, two in favour of the Middlesex station, on the north bank of the Thames, while the third favours the crew drawn on the opposite Surrey station. In spite of these bends the course is theoretically fair - the start and finish lines are exactly parallel, and in the unlikely event of the crews staying level throughout the race, they will both have covered the magic Boat Race distance of exactly 4 miles 374 yards.

The start of the race is marked by the University stone, a few hundred yards upstream from Putney Road Bridge and for the first quarter of a mile, as the crews pass the historic boathouses of Putney Embankment, the course is quite straight. Then begins the first Middlesex bend, said to be worth a third of a length advantage to the crew drawn on that station. The bend is almost three quarters of a mile long, and takes the crews past the Fulham Football ground at Craven Cottage and up towards the Mile Post.

The Mile is the first of the classic race timing points and is marked by a bust of Steve Fairbairn, four times a Boat Race oarsman for Cambridge in the 1880s, and founder of the Head of the River Race some forty years later. Oxford got to the Mile in 3 mins 31 secs in 1978 and Cambridge equalled that record 15 years later with the crew that brought an end to the Oxford dominance of the race which had spanned almost twenty years.

For the next two miles the bend in the river is entirely in favour of the crew drawn on Surrey (the south side of the river) and is said to be worth about one length to the inside crew. The first landmark after the Mile is Harrod’s Repository, the furniture warehouse built by the Knightsbridge store over 100 years ago. This fine Victorian building was constructed using bricks gleaned from the rebuilt Piccadilly underground station, and following Harrods’ removal to a computerised warehouse in Osterley it has now been converted to luxury flats.

Near the apex of the Surrey bend is Hammersmith Bridge, the only road bridge crossing the course. Cambridge reached this point in 6 mins 20 secs in 1998 with the crew which trounced the record for each subsequent marker all the way up the course. The crews pass St Paul’s School boathouse on the Surrey bank and the historic Doves public house on the Middlesex shore before reaching the two mile mark.

By now the race has reached that stretch of the course known as Chiswick Reach, marked by the narrow island, Chiswick Eyot, near the Middlesex bank, and a terrace of fine Georgian mansions on Chiswick Mall, the road which runs along the northern shore.

At the end of Chiswick Reach is the third timing marker, Chiswick Steps, reached by the 1998 Cambridge boat in 9 mins 56 secs, but then the Surrey bend begins to even out as the crews approach the three mile mark. Here is the point known as the Crossing where the best line for the crews lies directly across the middle of the river; this is where the racing craft lose the shelter of the shore and may be at their most vulnerable from the prevailing south-westerly wind. It was a wind from this direction that was responsible for the last sinking at this point when Cambridge went down in 1978.

Now begins the third and final bend in favour of the crew on Middlesex. The race passes under the girders of Barnes Railway Bridge and now there is barely three quarters of a mile to go. The crew that is down at this point has a daunting task ahead. Only twice in the history of the race has the losing crew at this point gone on to win the race. This happened in 1952 and again, 50 years later in 2002. On the Middlesex shore are the vantage points of the playing fields of Dukes Meadow, while the Surrey bank is marked by the White Hart public house and Mortlake Brewery.

The Finish Line is just a few yards downstream from Chiswick road bridge and here the crowds on Race Day are as densely packed as those near the Start. What those crowds witness as the crews cross the Line is the ecstasy of the victors and the despair of the losing crew. The Cambridge record breakers of ‘98 got here in 16 mins 19 secs, breaking the previous record by a staggering 26 secs. Whether one of this year’s crews can come anywhere near that time remains to be seen!