I usually leave the handle on and upright in the middle, I also run my rope through the handle to gently lower it then when it gets to the bottom, usually mud, I raise it up and down a couple of times to make sure it will stay upright. I like to lower it slowly because I don't use cement, instead I put fine gravel and sand in about half the buckett then finish the top off with fist sized rocks. I figure the gravel locks the air filled boo in, but have found if I just drop it sometimes the boo tries to float out or the boat will move some and the boo will try to fall over, the rope seems to take care of that.
I went diving Sat and came upon some boo in a 5 gal bucket, the first I have ever found diving, it was laying on its side, but it had been put out on a slopeing point. I attempted to upright it by pushing on the bucket but gave up after a couple tries, it was heavy, probably could do it by geting out on the boo and having more leverage but I did not want to burn all my air doing that. Lake is down alot, it was in about 13' to 15' of water and I saw no fish around it, but then again visibility was very limited about 5 feet. It looked really good compared to other structure I have seen.