afraser

I'm trying to redesign a fishing kite which are mostly single line square kites without tails. I'd like to use the kite along with existing fishing kites, so I need to tack it at least 35-45 degrees from downwind while maintaining stability even if wind drops to 10 knots. Additionally, the kite needs to have enough lift to pull a 500 gram object out of the water, ideally it will bounce from spot to to spot. Most of the kites on the market are square kites in the 80cm x 80cm range, with little ability to tack. There is a delta fishing kite (from Pauls fishing kites) that supposedly can tack more than 45degrees, but I've been unsuccessful at getting it to fly downwind enough (it stays mostly overhead, no matter how much I change the angle of attack). Can anyone suggest a design or alteration to the existing designs that would allow me to achieve the 45 degree tack with stability in 10 knots of wind? I already have a manufacturer and a supplier of cost carbon fiber spars, so really it's about using the best design. Thanks in advance.