Headiness on the Charles,

Tradition (not something to be taken lightly in this context) has it that the sun will shine this weekend, as hundreds of rowers take to the turbid waters of Boston's most prestigious river for the 17th annual Head of the Charles.

The autumn equivalent of the Marathon, hearty exercise before dining at Locke-Ober's, an imitation of the olden Argonauts: call it what you will, the Head remains one of the most panoramic events in the country.

It is also one of the best excuses for drinking beer and procrastinating about mid-terms, as the more than 50,000 spectators who usually line the idyllic banks of the Charles can attest. Veteran singles, the first of 18 races over the 5-kilometer course, kicks off at 9:30 a.m. on Sunday, and the day's program will conclude with the championship eights at 4:30 or so.

One unusual feature of the Head is its staggered start. The boats do not square off head-to-head; they each race against the clock. The only classic "confrontations" you see come when one shell picks up enough steam to overtake another.

The flip side to this is that each crew has its moment in the sun, no matter how poorly it does. The boats glide one-by-one under the packed Anderson Bridge, and throngs of enthusiastic well-wishers lend their support to each vessel. Only when the times become known a half-hour after the event ends are the winners determined. For the fans, the results often remain unknown unless they read the agate type in the next day's Globe.

But that is not the point. Participants from across the country come to ply the Charles, and for some crews the endless hours of fall training are compressed into the quarter-hour required to complete the course. The Head course is longer than most regattas, making it an extraordinary test of stamina. The winding curves and bends of the river make the crews' coxswains important players in the race, since steady steering can improve a crew's position significantly.

Still, last year, a handful of the racing boats packed up their trailers and left even before the results were announced. If you talk to the rowers fresh off the river, you probably will not be albe to identify with the slightly-inebriated stupor that comes from a long, hard race. You will instead be hypnotized by the flow of the boats sliding down the river, the harmony, the alluring but misleading ease displayed by the crews as they perform one of the most difficult physical acts.

Get heady. Be there.