It's like that story about those four guys, Anybody, Somebody, Everybody, and Nobody. I saw your post and thought, "Anybody knows more about mast rake with a spinnaker than me, Everybody can see that post, so Somebody will answer it." Now I feel guilty because Nobody answered you.

That's not typical of this forum.

Last time I opined on mast rake, Mark Michaelson was kind enough to draw my attention to several facts his experience tells him are very important. Turns out, I'd forgotten reading those same things in Rick White and Mary Wells' book, "Catamaran Racing: For the Nineties" That's a book I recommend very much - and not just for racers, by a long shot. It makes sense, is approachable, gives equal time to other points of view, cites empirical research, teaches fundamentals of sailing, and will make anybody a better sailor.

As I mentioned above, my experience and the opinions I've gotten from much better sailors is limited to non-spinnaker boats, so I'd recommend you post a "Hey Spi sailors, how does a spi change your Rake?"

Asymmetrical hulled boats like the H- and P-16 need lots of aft rake, for the reasons below and others. Symmetrical hulled boats like your Nacra 5.2, in fact all boats with boards, can use the following game plan for rake, with some success:

Here's the short story, the supporting theory follows:

Sounds simple, and it is, provided you understand why it works. All this was aimed to get the rudders slightly "in the game" in providing some lift to windward, but not so much that they were creating damaging amounts of drag.

According to Rick and Mark, and borne out by my own experience, the most significant impact of rake is on the true tendency of the boat to turn either into or away from the wind. (Just for a moment, don't think about the feeling of "pull" in the hiking stick - we'll handle that later, and it's only partly influenced by mast rake. More below but for now, take my word for it.)

The boat's tendency to turn upwind (or down-) is determined by the positions of two things: One, the center of effort (CE) of the sails - the net point at which all the lift those bad boys make is centered. Two, the center of lateral resistance (CLR). Think of the CLR as the center point of all of the resistance to leeway made by all the wet parts of your boat, boards, hulls, and yes, even rudders resist leeway, under the right conditions - more below on that.

Push downwind on the stern and upwind on the bows, she's gonna turn upwind, until you lift the sterns with the rudders and then she'll go straight. In other words:

Keep on not thinking about the pull in the stick! We'll get to that later, it's a different thing!

You can move the CE around while under way with the various sail controls and you can even steer your boat that way, but when you set your sails to go upwind fast, you don't get a lot of choice about where the CE is, except by where you rake your mast. This is done, on the 5.2, like most boats, 'on the beach'

You can move the CLR around on the water by shifting your weight forward or back, raising or lowering your boards (if you have 'em) but again, when you're trying to go to windward as fast as possible, your hulls need to be just right, and there's an optimum setting for your boards, too.

You want to get maximum lift to windward while setting all your running controls for best boat speed.

That means you want your rudders to generate some lift to windward, too. The way to do that is to induce some Weather Helm with the rig, so you can balance it with the rudders, and they will be generating some lift. "Some" means just enough that you aren't creating so much drag with the turned rudders that you lose the benefit.

Okay, we're still ignoring the feeling of pull in the hiking stick, for just a little while longer...

"Cat Racing..." says to set up for your best course to windward, the one that gets you the most progress to windward, not the highest you can point. While holding that course, you want to see how straight your rudders are (not how hard the stick is pulling). You can check this easily by looking at your tiller crossbar and seeing how far to windward you are pulling it. Compare the bracket where the stick attaches to the center of your tiller crossbar to the center of your aft crossbeam. Use your traveler jam cleat for a guide. Rick's guideline for "some" weather helm is that your tiller crossbar should be a quarter inch to windward of the center of your crossbeam, while traveling in a straight line, going to weather.

To adjust this, you simply rake your mast aft to make the tiller crossbar come to windward; moving your mast forward will cause you to sail with your tiller crossbar more to leeward. (All this assumes you've got no significant 'play' in your rudder system - the blades are shimmed into the castings, and the rudder pins aren't worn.)

Sounds simple, and it is, provided you understand why it works. All this was aimed to get the rudders slightly "in the game" in providing some lift to windward, but not so much that they were creating damaging amounts of drag.

Turning a rudder away from wherever it 'wants' to point is hard work. It's only manageable at all because a properly tuned rudder is angled so a small fraction of the rudder is actually forward of the hinge or "pintle." That forward part has tremendous leverage, and balances the forces acting on the trailing part, allowing mere human muscles to generate enough deflection in the rudders to shove around the back half of an 18 foot boat under tremendous loads from it's sails, hulls, etc. That's why when your rudders aren't all the way down, they're hard to pull to steer - it's not just that they're further aft; it's that they no longer have enough of them forward of the pintle.

That's why mast rake seems to affect the way your hiking stick pulls: the more you rake the mast aft, the more you need to steer so as to deflect the rudders underway to generate lift to windward, and the more you will "feel" any imbalance in the rudders! That's why most folks confuse rudder rake with helm - if your rudders aren't tuned, you feel it more with aft mast rake. That's why you need to ignore the 'pull' in the stick and concentrate on rudder deflection when measuring your mast rake.

If your rudders pull too hard, it's not necessarily caused by a 'wrong' mast rake. Sure raking the mast forward will seem to reduce the effort you use to hold the stick, but only because it reduces the forces acting on the rudders, and those forces can be quite beneficial, used the right way!!

So, first check rudder deflection as above, and rake accordingly. If the stick is still hard to hold, then rake the rudders forward until the stick is easy to hold. Don't go too far, or you'll experience a tendency for the boat to turn off wind when you let go of the stick, which can be disastrous.

Again, all this is up for modification by the spinnaker skippers out there, applies primarily to symmetrical - hulled boats, and there are other points of view, some held by very successful skippers. I'm slow to argue with success on the course - racing is a pretty good gauge of where the rubber hits the road in the "theory vs. opinion" dept.

I do sometimes think that even really good sailors can have the occasional misperception about tuning a rig and overcome it with sheer brilliance out on the course, all the while citing their success as proof of logic of the tuning of their rig. So I do like to understand why a tuning tip works, too.

Hope this helps!