Thank you for all your input. Keep up the discussion.
OK, here is my update. I'll let you know if this "fix" worked at the end of the summer. If it doesn't work, I'll let you know how the swim back to shore was.
When I took the mast to the P-51 Mustang welder, right away he noticed that this was not the first time the mast needed repairs. There is a previous weld, from a previous owner, lengthwise close to the base of the mast. Since I've been using the mast for 3 plus years with no problem, I take that as a positive for trying another weld.
Here is the link to a pic of the previous weld. It runs lengthwise, from the left of the arrow to the cleat. It is about 6 inches long. It's been grinded down, and I just didn't notice it before. (I could never be a detective.) http://www.flickr.com/photos/38884077@N05/3576028396/
So, the welder did his thing with the new split in the mast, and you can see his work at the following link. He thought it might be good to have more than the single weld at the split, to possibly give more support. Pic is prior to painting.
As I said, I'll let you know how it works. If it doesn't, I'll let you now how much a new mast costs, and how cold the water was. http://www.flickr.com/photos/38884077@N ... otostream/
Hope the links work, and thanks again for your thoughts
Happy sailing! - Paul B.