elevated above the water surface 0153 fig1 is an explanatory diagram of a preferred embodiment of a delta airfoil aft mast lifting sail rig apparatus 9 employing an efficient delta shaped sail or wing 23 with a low center of effort 23 ce the delta lifting sail or wing 23 is preferably light in weight and may be solid or inflatable similar to conventional delta shaped hang gliders and kites fig1 shows the same principle as the aft mast lifting sail rig apparatus 3 or similarly a reinforced lifting sail rig apparatus 4 and method of operation with the embodiments shown in fig1 through 6 except with a delta shaped lifting sail 23 the shorter height of the high lift delta shaped sail 23 has the advantage of a lower sail force center of effort 23 ce with a large sail area resulting in a smaller heeling moment with a large sail driving force the delta airfoil aft mast lifting sail rig apparatus 9 may comprise a fixed vertical mast 50 with a short mast sprit 44 projecting forward at the top of the vertical mast 50 for supporting the delta lifting sail 23 the vertical mast 50 is positioned aft of the delta lifting sail 23 without aerodynamic interference the mast sprit 44 is laterally supported by two widely spaced starboard 62 s and port 62 p forestays attached to an extended beam planning hull 14 the aft vertical mast 50 may be supported by two widely spaced starboard 64 s and port 63 p backstays not shown the center of lateral resistance 18 cr is located on hydrofoil 18 s on starboard side of extended beam planning hull 14 and hydrofoil 18 p on.