I'd be cautious,
I'd be afraid of having the CB swing down, hitting the front end of the trunk and spliting something. If you can, maybe you could put a line around your boat, cabin to the stub keel, a big loop, to keep the CB from falling uncontrolled. Many hardware stores have some kind of flat metal strips, 1/8 x 3/4 in. You could use that to slide up into the trunk between the trunk and the CB to clear whatever is in there. And maybe you can replace the CB wire with a good grade of 1/4in. dacron line. My CB weighs 50-60 lb. and 1/4 in. line would have more than enough strength. Better yet, if you can put your boat in a sling things can be done fairly quickly. Have a good day!!!Tom