Two refinements were selected for the design following the completion of the 2nd iteration of Model No.3.

A form of double-clewed jib has been chosen for the sail. It's a variation of the 'shunting staysail' and will allow the mast to remain stationary. When shunting, the sail can be easily moved from one end of the outrigger hull to the other using a single continuous line wrapped around a capstan. A single continuous line affixed to the leeches serves as the clew attachment points for the sheets on alternate tacks.

This arrangement creates a freestanding luff that must be pulled tightly to be reasonably straight. The luffs must have wire rope sewn into the leading edges and wire rope is needed for the lines. Over-center levers with positive safety latches adjacent to the capstan are needed to tighten and lock the luff lines. The sewn-in wire rope provides an aerodynamic benefit in creating a slightly rounded leading edge that doesn't require precise alignment of the leading edge with the relative wind.

Rather than being side-mounted as on the 2nd iteration of Model No.3, the keel/rudders should be similar to the design developed by Ted Lamont for his proa, About Face. As he points out at his website, large, side-mounted rudders can create a dangerous yawing motion in heavy seas coming from astern.

Small fore and aft adjustments of the keel/rudders for steering balance, and retraction for beaching, can be made with a simple hydraulic system powered manually by rotary vane pumps using water as the working fluid. Such a system, coupled with a mechanical load release mechanism, also allows the keel/rudders to fold if they hit something.

Note: If the separation of the sail and keel/rudders is to be no more than 60% of the main hull length, to be force-balanced the boat is limited to using a rather short sail. I expect that a craft of my design less than 10 meters LOA will, as a consequence, have lower performance than an equal length proa or catamaran with live ballast because they can carry more sail area. If the wind is strong, then the force-balanced boat can compete. This may not be a deficiency in a family cruising boat. In large sizes (above 15 meters) when live ballast is of little consequence, it should perform very well.