There is an excellent article in Rick's book "Catamaran Racing for the Nineties" written by Randy Smythe, I think, about sailing with a kite on a cat.

To set the main traveller correctly you set it in the same manner that you would on any point of sail off the wind. That is, pull the traveller in until the bottom leeward telltales stall then let the traveller out until they flow again. You then of course trim the upper telltales with the mainsheet.

On a cat with a kite you, of course, set the main traveller after you have the kite set. The traveller ends up almost centred. What tends to happen when sailing with a kite is that you generate so much apparent wind that you end up with sail settings that are almost close hauled to the extent that no matter which point of sail you are on you are sailing like you are going to windward. This is according to Bethwaite, I've never sailed with a kite so can't tell you from experience.

The article in Rick's book also talks about setting the jib and the importance of not having it too tight as you can easily create eddies on the leeward side of the jib which can adversely affect the spi. It is important to have the jib a little on the loose side, set the jib in the same manner trim it until the telltales stall then loosen it until they flow nicely - according to the author of the article, again I have no personal experience of this.

Rob.