Rudderless Sailing

u/alethia_23 explained it well, but the basic concept is understanding CLR and CE. The Center of Lateral Resistance (CLR) is the pivot point of the boat, which can be adjusted by weight but is generally the centerboard. The Center of Effort (CE) is the average point of all the force put on your sails by the wind. If the CE is fore of the CLR, the boat will fall off as you are pushing above the pivot point. The inverse is true for pointing up. So, to get CE fore: trim jib, ease main. Aft: trim main, ease jib. You can also steer the boat with weight by using your body as a tiller: move to windward to fall off and move to leeward to point up. It’s important to note, however, that as you fill off to around a broad or low beam your weight becomes much more important for steering the boat because trimming your sails at this point will only serve to depower them. Note: You need a pretty hard chine to do this as it will act as the rudder