Alnims: The only function of the traveler is to control angle of attack. Here's one example of how you can use it. Assume you're closehauled and you're hit by a sudden gust of wind and the boat heels over. You could use your mainsheet to bring the boat back on it's feet but the mainsheet is also used to control twist and draft position and you may not want to mess with those element. The easiest way to bring the boat back on it's feet is to drop the traveler down (change the angle of attack) to reduce the heel. As soon as the gust passes you'd return the traveler to its original position and sail merrily on your way because the original shape of the sail has not changed. Next time you're out sailing give it a try and see if it works for you.
What's the sailing weather like this time of the year in Japan??
What's the sailing weather like this time of the year in Japan??