Raising the mast on the smaller boats
I looked up the O'day 20 and was surprised to find that the mast is actually shorter than the one on my 192. I think this is probably because the 20 is a masthead rig and the 19s are fractional. Anyway, raising the mast should be comparable in difficulty. Having been accustomed to the relatively effortless rigging of a Potter 15 when I bought the 192, I was a bit intimidated by the much larger spar and considered gin poles, stabilizing lines and 4 part purchases but, with a little practice, thay have turned out to be unnecesary. Echoing the previous posters, what is really valuable is a mast crutch with a roller. The one I have is telescoping (it's called a "Mast Up") and holds the mast low for trailering and raises about 4 feet to make the lift and drop easier. I hook the jib halyard to the stem fitting on the bow, I stand on the closed hatch next to the mast and pick it up with one hand (it weighs about 40 lbs, it feels like picking up a suitcase packed by my wife) With my other hand, I take up the slack on the jib halyard and hold it so I can move the first hand underneath it for the push the rest of the way up. Once the mast is lifted past 45 degrees or so, very little strength is acutally required. When the mast is vertical I tension the jib halyard as tight as I can and cleat it. It holds the mast up while I go to the bow and attach the forestay. Positioning the boat when rigging so that there is little or no crosswind is a good idea to keep things under control, but using my technique you will never actually let go of the mast until it is all the way up and supported against side loads by the shrouds.Enjoy your new boat! I think boat of this size are the ideal compromise between accomdatiion and ease of rigging for those of us who seldom spend more than a weekend aboard at a time.