No question about it it is ALWAYS best to unstep the mast for the winter!!!!!
1) Much easier to cover the boat when you aren't trying to fit the cover around the mast and standing rigging. If mast is well supported and covered, it can be used as part of cover support. I would rather have mast stored inside or on covered rack. but use as main beam of cover is still better than leaving stepped.
2) Mast will last longer when not subject to stress and strain of winter weather against a mast that can't move in reaction (boat is rigidly fixed preventing it from heeling i nrelation to wind)
3) Less stress and strain on rigging (stays get a chance to "relax" over Winter. With mast unstepped and stored inside (or at least covered over) it is out of weather and avoids sunlight fading of paint or weather effects on anodizing). Rigging on a stepped mast can experience moisture creeping into the lower swage fittings, as water freezes it may crack the fittings weakening them severely.
4) Running rigging (halyards) will last a lot longer on an unstepped mast protected from the weather. I remove my halyards each Fall to wash out, much easier to do after mast is unstepped. Plus no matter how well tied off, halyards on a mast left stepped all winter will find a way to clang against the mast damaging both mast and halyard.
5) How do you intend to fully inspect everything (especially near the masthead) if the mast is not unstepped? Can't be done properly (well ,actually can't be done at all on a small boat like the 23) without unstepping the mast. All you need is one broken strand near the upper end of a shroud or fore or backstay to bring the whole rig down costing many times the cost of unstepping and storing the rig. By unstepping the mast for the winter, you can spot trouble early and fix it.
5) Not only are the shrouds being potentially damaged while exposed to the winter's weather, but the chainplates will remain under strain all winter. Once again, the strain wil lbe worse than normal due to the inability of the boat to move to lesson that strain. This can cause the sealant around the deck holes to loosen or fail since it wil lbe less flexible in cold weather. A small leak becomes bigger as water gets in and expands.
6) less strain on boat, as mentioned chainplates and area under mast step will be better off without force of mast pulling up on chaniplates (and thus bulkheads) and pushing down on deck (again, not to mention effect on bulkhead).
If this were a boat with a keel-stepped mast (which, other than the first pop-top version, the 23 is not) having the mast stepped all winter risks water entering the boat through the mast and around the mast partner (hole in deck), this can also lead to corosion of the mast step and mast butt (lower end of mast).
On the 23 you could unstep the mast yourself and if you use it as the ridge pole of the cover, it won't cost anything (on larger boats the price to have the yard unstep and store the mast, then re-step in the Spring is a consideration, but still A LOT less than repairing damage caused by a mast left stepped for the Winter!) Boats left with the mast up are also far more likely to be blown over by a winter storm, resulting in very expensive damage to your boat as well as surrounding boats (less of a problem if boat is on a proper cradle, like the original shipping cradle. However, not many yard still use cradles. Brownell Stands are more efficient and easier to store.)
Some boatyards actually REQUIRE that ALL masts be unstepped, I really don't understand why that is not the case at ALL boatyards given the potential damage caused by even one boat boat being blown over in a storm. Eve nif boatyards don't require unstepping masts, I would think Insurance companies would certainly require it to avoid having to pay for the damage caused by leaving the rig up compared to unstepping it. Our late friend Joe had his insurance company try to declare his at the time fairly new 222 a total loss after his mast came down due to a failed chainplate (this even though he always unstepped the mast for the Winter). The same thing happned to a friend of mine when the mast on his 42' trimaran failed and went over the side. As I say, it blows my mind that insurance companies don't require unstepping the mast while hauled out.
If ,after all this good advice, you still decide to leave your mast stepped all Winter, at least remove the sails!
