silly question about roller furling
I'm new to sailing... I've only been out once, and it was an 8 day ASA 101/103 class. Our boat was an IP440 with roller furling genoa and main (mast furler). I was thinking back on it and thinking about some of the reefing stuff I've read in other threads today, and I guess my brain stopped working.
What keeps the sails rolled up? I know to furl them, you pull on a rope that turns the furler and it rolls it up, but I don't remember ever cleating that line off or seeing the captain cleat it. What prevents the sail from unrolling if the wind picks up or something? This seems especially problematic for the genoa. The captain isntructed us to keep the genoa sheets reasonably tight when the sail is furled so that they can be used as something to grab onto in an emergency if you're falling overboard... the tension should unroll the sail unless something is keepng the furler in place. As far as reefing, there must be a way to get the furlers for both sails to stop at a given position so you can trim the sail with the sheet/outhaul and it won't just continue to unfurl.
What am I missing or forgetting?