I can see two good reasons why Cape Dory and most other sailboats sail at anchor:
The anchor lead is usually off to one side or the other, giving the vessel an uneven stance when pulling back on the rode, which starts the oscillations.
More windage in the bow due to the sheer (ie; the bow gets more wind than the stern does), will cause the wind to make the bow fall off before the stern. Combined with the anchor rode restricting the bow's movements, it will act like a "kite", and sail.
Roller furling and other gear at the bow act as small inducements for the boat to fall off on one or the other side and start to sail.
The solution is to try to put the stern directly in line with the bow and the wind direction. As it starts to take off on it's sail, a riding sail will then help push the stern back into the alignment that we seek, killing off the oscillation. Other than presenting the boat at an angle to the wind (as with a warp to the anchor rode), to get a predominant direction where the boat will stay put (but put a lot more strain on the anchor and rode combo), and also an anchor rider, I can think of no other way besides a riding sail, to limit your movement while at anchor.
Cheers!
Larry DeMers
s/v DeLaMer
Cape Dory 30
Patrick Turner wrote: I don't have a solution....the privious message sounds interesting and I'm going to give that a try myself...but I believe one of the reasons Cape Dory's swing or hunt at anchor is because of the "cut-away" forefoot design. Because there is a lot less keel under the forward half of the boat then the aft end of the boat, there is much less lateral resistance to the wind pushing against the side of the boat. So as soon as it feels a little wind against one side of the nose.....it tends to fall off and kind of sail over a bit till it comes up tighter on the rode and then starts over.
Pat
demers@sgi.com