Ditto, here, nies. Now that the sun is beating down relentlessly, thought I'd revive your thread since I missed it first time around:
Wanted to make a boom tent w/o actually buying anything with stuff on hand and in regular use on board. Had the tarp that I used 2 years ago for BBB-2013. Problem was that I didn't "experiment" with it 'till I needed to use it. Poor decision on my part. Naturally, I waited until after dark and wind picking up, and hadn't figured out how to secure the tarp. Lots of fun!
Sooo... I raised the mast and boom in my drive-way, tossed the tarp over the boom, used same sized bungees from the four corners to the aft cleats and two pulleys that the PO had mounted on the cabin roof. That left 2 grommets on either side. I used two fenders as weights and strung them between the grommets and left hanging over the side. You can use the fenders vertically or horizontally. Less than 5 minutes to set up. So easy a blind person could do it by feel alone. No more worries about getting it set up before dark (For some strange reason, a lot of gabbing occurs after dark in the cockpit of a 23! - ain't that right, Bob23?).
Of course, head room still isn't great but no problem sitting/sleeping. Great protection from rain/sun/sea-gull guano. When used along with my raised cockpit grid and air mattress - perfecto!
81 CP16 Pegasus
P.S. I've given up on a Bimini that can be used under sail. Don't know how people do it. I'm 6'2 - hopeless!