Ok, so I thought I'd ask you guys: when I go out by myself and there is heavy wind, I sail with the jib only; People whom I trust have told me this is the way to go if I have to sail with only the one sail, also I've tried it and my boat won't point worth a shit if I only have the main up. This being said I see people (both out on the lake and here) sail with just the main all the time! Is this something that is commonly understood or is this something that is more noticeable on my little centerboard sloop or what?

I am not a sailing expert (by a long shot) but I go on short sails with only a big genoa, all the time. Because I am lazy. Blame it on the people who invented roller furling.

If your jib is large (like a 150) and goes aft of the mast it will be more balanced and easier to steer the boat than with a smaller jib.

On a longer cruise I would definitely use both sails because the mail will help the jib.

There is one thing to keep in mind when sailing under headsail alone. It puts uneven pressure on the rig. I have read that if the wind is big enough you need to balance that pressure on the backstay with something. If you have a topping lift you can tighten it up some and crank down on the mainsheet to add some aft pressure on the mast. Obviously mid-boom sheeting doesn't work as well for this.

Definitely like using the genoa alone when by myself tho. I've done it a number of times when singlehanding just to make it easier to control and reduce sail in a hurry.

How well your boat will sail with only a head sail or only a main has a lot to do with where the center of effort and the center of drag are located on your boat. Generally speaking you can estimate how well a boat will sail on only a head sail by how large the main sail is in comparison to your 100% genny.

My Ranger 26 has a relatively small mainsail and sails very well on my various genoas. My old yawl sailed well on it's gaff rigged main or with a genny and mizzen but not so well with just a genny. My 1rst boat, the Bimini Queen design I built with a friend had a very big main and a club footed jib. It sailed fairly well with just the main.

There are occassions when I will sail with only one sail aloft. Generally though, it will be the main perhaps 90-95% of the time.
One thing that I have noticed a lot when cruising, like up in Lake Huron, the North Channel, Georgian Bay... for a couple of cruises, I only saw one sailboat with both sails aloft for every 10-15... even 20-25 sailboats that had ONLY the foresail up (not the main), or simply motoring. Could not for the life of me figure out why I'd have both sails aloft (whether reefed or not) and 98% of the other sailboats would only be flying a large foresail (if that). Finally 'clicked' for me last summer, when I finally noticed what 'appeared' to be the average age of the sailors on those boats. Nothing precise, but they appeared to be from late 50's into their 70's. Even many of the 'younger' sailors did the same. Notorious for building strength throughout the day, from light to very heavy at any time... my belief is that many sailors (especially the older ones) would rather SIMPLY furl the genoa/drifter, whatever, rather than attempt dealing with the 'mainsail tap-dance' in heavy air. Whether that's the reason or not, I suspect that the day will come when I will likely do it for that very reason. Just can't see being 65 or 70 and playing a tap dance up forward, especially if sailing solo.

All that being said, I will admit that on occassion I have used the genny (only) when it's pretty heavy air with repeated wind changes and heavier gusts when sailing solo. What I call 'fractured air'. But, still, I find she sails better with both reefed, rather than just one sail. If relatively constant heavy air, the main, especially if (close) reaching and tacking. Not sure if any of this helps...

I will admit that one of the reasons I dont use the main all the time when sailing alone is that the little nylon slides that go in the slot in the mast get stuck and require you to leave the cockpit and help them aloft.

I know that west marine sells a can of "nylon slide lube", but I haven't tried that simple fix.

I really enjoy my cheap little boat, and dont regret buying it, even with all the repairs I have made-because I am learning so much. BUT, I do regret buying a boat with a tiller. It's just such a nuisance when sailing alone.

I have a "Tiller Tamer" but it makes the cockpit into an obstacle course.

I am always building stuff at home and every time I am out sailing I try to think of a good way to lock down the tiller.

Many have stated the "right reasons" for one sail plan or another. (lee helm, balance, etc.

My boat balances reasonably well under a large genoa or main alone.

I suggest the reason my single sail combo is the main is that I do not have roller furling. It's easier to raise the main and go.

Thanks for the great answers guys. It makes a lot of sense too as my main is obviously the smallest of the 3 sails I have for my boat. I don't have any roller furling here, but I have a topping lift for the boom, so in any emergency while singlehanded taking the main down involves the boom crashing down on the cabin top, so that's another reason that when I sail by myself I just use a hanked on 160 genny. (on second thought maybe I just need more friends.)

also: I would have to disagree with you about the tiller, though. I learned to sail on bigger boats with wheels, and I much prefer the more intuitive feel of my tiller, I think I would want a tiller even on a larger boat; I just want to get a wind vane.

Until you get a mast top vane you can tie yarn on your shrouds. I actually think in light air that works better.

You might be able to use regular, hardware store variety silicon spray on your sail slides, brainula.