Ahhhh - so if you're not a boating newbie then we don't have to be qute so nice to you
We try to be on our best behaviour with total landlubbers
...anyway...a Southern Cross has a cored hull, which is a bad, bad thing in a neglected boat. They were sold (mostly as unfinished shells) to people who wanted Valiants but couldn't afford them.
Because they were owner-finished inside, you are almost guaranteed that there are holes through the skin and into the core, and that the core is wet - hence rotten in places. Besides, they are fat, slow and ugly and sometimes the kindest thing to do to a boat is just let it sink as nature intended...