I own a Cal 21 as well. Here's what your cockpit should look like absent the winch!
As you can see, and already know, it get's in the way unless you're just launching to do a quick day sail.
It's easy enough to get it out of the way, especially if you're to leave the keel lowered. You should have a board, a stout board, that spans the cockpit seats that a trailer winch is bolted on to. You can use it with the winch pointing down but it's easier if you have a hole cut in the board that your winch cable passes through and you'd then leave the winch upright.
What do you have on the aft end of your keel for the winch cable to attach to? I have a steel ring that was on the boat when I bought it. It's actually a piece of heavy steel rod bent and welded into a ring with a tail on it. The tail is embedded in the lead of the keel. Mine was adrift when I bought it and that made for some tense raising and lowering along with the need to keep a certain amount of tension on it to keep it in place. Some thickened epoxy took care of that and secured it quite well in the keel.
I tried line on the winch but soon went back to 1/8" aircraft cable from the local hardware store. But I still did not have a good method of securing it out of the way when sailing and my keel trunk grate did not fit properly or the keel stopper. The device below and a Home Depot boat hook (broom handle) solved that problem.
The previous owner was in the habit of diving over the side to attach and unhook the cable from the keel and I tried that for a season or two. But when you endeavor to sail as long as there is no ice on the lake, the prospect of diving into thirty degree water to attach the cable daunts.
With the grab and go hook I lower the keel and then release the hook, all from the cockpit. Reattaching it is a bit more of an effort, but I painted that ring international orange and I can see it well enough to hook it with the grab and go on the boat hook.
As mentioned, you should have a keel stopper, which is a long tapered board hinged to a shorter board, that resides in the keel well when your afloat. It does hold the keel somewhat in position if you have not pinned it in the cabin, but it mostly serves to keep the cockpit dry. The trunk footing or hatch cover sits over it and your feet stay dry. You'll see a bolt through the aft end of the keel well and that is designed to go through the short board off the hinged portion of the keel stopper.
Just for fun, here's a well known sailor experiencing the benefits of well trimmed sails and the boat virtually steering herself!
Here's the same fellow the week before Thanksgiving at the fall knockaroach, some time after we removed all the ice from the cockpit!
Here's the Emily Marie
in more benign conditions.
Here are a couple of photos of some modifications that have occurred over the life of the boat to make it a bit more usable while sailing.
You can see the "pockets" in the gunwales in a previous photo.
Here's a link that will provide you with much information and will give you a schematic of the keel stopper if you're lacking one.
Cal 21 Sailboat
The boat is a bit tender and easy to over power but SailorTJK above will verify that you can have water pouring over the gunwale flooding the cockpit and she'll not go over. A reef in the main and you'll still more than keep up with anything of similar size out there. Simply put, if you cannot have fun sailing this boat you're likely to never have fun sailing a boat. You've got a keeper well worth any time you invest in her restoration.