While the A-spin seems to be intended as a simplification, it has its own arcane set of practices that must be observed and may actually make things
more complicated.
Instead of sailing dead downwind, the boat may sail on more of a broad reach at higher speeds and not necessarily on a steady course. As the boat heads up-wind a little, speed increases and the sheet is trimmed in and the kite operates more like a large Genoa jib. After Speed is built, the boat may bear away and head more directly downwind with more speed. Then there's the variable of how tight or loose to trim the tack and head of the sail. As the boat heads down and speed decreases, the crew shifts weight to try to heel the hull to windward in order to get the kite to rotate to windward to expose more surface area to the direct wind.
J-105 Spinnaker:
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