Measuring the distances..

With the launch window during high tide lasting only two hours and a certain safety margin of water depth necessary, it is vital that the distances flown are measured quickly - and with big prize money and prestige at stake - extremely accurately.

Once again this year's International Bognor Birdman will employ the most advanced technology provided by Leaderboard Ltd, with bespoke software enabling real- time display of wind speed and direction, time in the air and, of course, distance flown.

Distances flown will be measured using three electronic theodolites. Set up level with the launch platform and on the 100 metre line, the units use triangulation to accurately pinpoint the competitors' landing position.

On splashdown the angles recorded electronically by the three measurement stations are entered into the Birdman computer which instantly displays the horizontal distance flown in any direction and calculates any small margin or error which can occur through fluctuating tide swell.

In addition to the giant electronic scoreboard keeping competitors and public up to date, a separate indicator board on the launch platform will show wind speed and direction to help pilots judge their best moment to take off.

The successful jackpot prize winner must also cross a line of marker buoys set 100 metres from the end of the launch ramp. Touching the water before splashdown does not count against the competitor. The final distance flown is all that matters in this unique competition.

A cash prize is also available for the flyer who stays in the air the longest, regardless of distance flown. In 1999 for the first time this was not awarded to the furthest flyer as might normally be expected, and this has heralded the appearance of aircraft designed to trade forward momentum for lift, giving the ability to 'hang' in the air longer.