Maybe I’m over thinking this problem. I’m trying to determine the best location for the mast in the 18’ HW that I am converting to sail. The canoe does not have a mast seat. I can mount the mast step in one of three locations, in front of the bow seat, behind the bow seat or in place of the quarter thwart. I don’t want to have to move it after it’s mounted. Drilling holes through the bottom of the canoe twice is not an option. The distance from the bow to the three locations is 56.5”, 70”, and 73.5” respectively. I have a 55 sq.ft. sail rig. The distance from the mast to the Center of Effort is 3’-2” more or less. The canoe has sponsons with oar locks mounted at the center of the canoe. Therefore the center 8” of the canoe is not available to mount the leeboard bracket. The leeboards would have to be mounted ahead of or behind the oarlocks. If I mount the mast in front of the seat I can set the leeboard bracket directly under the CE but that location is ahead of the center of the canoe by 1’-1”. If I mount the mast behind the seat the Center of Effort and the leeboard location would fall at the center of the canoe but the oarlocks would preclude that location. I would have to move the leeboards ahead of or behind the CE by at least 7”. If I mount the mast at the thwart location the leeboards would, by necessity, be behind the CE and behind the center of the boat. My thinking at this point is to mount it in front of the seat. That location affords the best option to adjust the location of the leeboards forward or behind the CE. Sooo… what do you think? I went through the forum archives but I couldn't find the total answer. Thanks, Jim C.