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The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.
It's probably possible. According to the definition, there would be no permanent stay between the mast and the deck of the boat. The sail would have a built-in wire or stroong rope luff. If you do not have a vent between the anchor locker and the deadlight on the foredeck, that space would likely be the favored spot for attaching the tack of a dazy sail. The spinnaker pole downhaul, if currently run through a block there, would need to be moved further aft to just in front of the forward hatch or forward to the bow just in front of the anchor locker, which might be preferable. I have no idea how effective it might be on a C-25.
Why not? All it would take is a fitting on the deck for the tack, and another spinnaker-type halyard. (...and maybe another winch.) But it probably invalidates your C-25 PHRF rating...
Several years ago Sail magazine did an article on installing the deck hardware for such a sail. They recommended reinforcing the deck since, on most boats, it is not designed to withstand upward pressure. You can probably find the article in their archives.
Notice: The advice given on this site is based upon individual or quoted experience, yours may differ. The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.