I don't have any pictures, but I use a "brake winch" mounted on a 2x4 to safely and easily crank the mast up and down while in the water, on My Bristol 24. My boat has a very heavy mast. The brake winch allows you to crank under control in either direction, with no chance of sudden movement. I use a 8' 2x4 that has a braket on the bottom that pivots on a bolt at the front of the mast step. At the top of the 2x4 is an eye bolt for a line to the head stay plate, and on the mast side, another eye bolt for a small block. About halfway up the 2x4 is a 1000# hand brake winch. The cable from the winch runs up through the block and hooks around the mast as high as I can reach. My spinnaker pole topping halyard hooks to the winch cable to keep it from slipping down the mast.
To keep the mast in line, I attach chains on each side of the mast at the base of the life line stanchions. The chains are the correct length to allow enough slack for the main, and jib halyards to hook on the chain in line with the pivot pin of the mast base.
To raise the mast, I slide it back, and pin the bolt into the mast hinge. I attach the line from the top of the winch board to the head stay plate. Then run the winch cable up the mast about 10 feet, and attach the topping lift to it. Hook the halyards to the chains at the correct point, and tighten, and secure. The winch is then cranked, raising the mast. Easily done by 1 person. I usually also attach the spinnaker halyard to the head stay plate and keep tension on it with the genoa winch on the mast, in case the winch cable should come loose.
With practice, it only take an hour or less.