Dave, you write with much sense but I have seen too many good boats stored afloat , even with good covers, suffer needlessly. Their hulls having become heavy, saturated and soft, their brightwork deteriorated, hull repairs put off. If a hull is entirely sound, not likely in a hundred year old boat where structural work is almost an ongoing winter requirement, then I would agree with you, store afloat. Another issue is that developing requirements for structural work beneath the waterline are not seen for obvious reasons.