Fast Forward... Mast back... THe differences

I have been playing with the mast on my H16 trying different things with adjusting the mast forward (towards the bow) and back towards the stern... Here is what I have seen in the reactions from the boat. Obviously with the mast adusted forward, the Main sheet has WAY MORE room to pull in and has more distance before the boom gets close to the tramp.. Sails are in Awesome shape, but when the mast is in its "proper" location, I can sheet in, and I can almost max out the bock, and the boom is within a foot from the tramp... WIth the mast pulled forward, I can sheet the main ALL THE WAY IN TIGHT, and still have about 2 feet before I max out my pulleys. BTW, I have made custom attachments (over the stock ones) to really adjust the mast forward and back..

Here is what I find in sailing it. WIth the mast forward it tends to bury the nose more under a good wind, so I tend to hike out with my weight towards the rear of the boat, and that tends to keep the nose out of the water, but she still LOVEs to bury that nose, AND during a heavy wind flying a hull, she REALLY likes to turn into the wind (I have to fight her to keep her on the line) ALSO<, It feels faster, and is more reactive to the wind than with the mast stepped back.

WIth the mast stepped back, it seems slower,,,less reactive, and it pulls the front out of the water and feels ars heavy. I also feel as though I cant sheet the main in all the way, cause the boom gets really close to the tramp

Has anyone ever played with the mast and noticed the differences, or can tell me if I am correct with my conclusions..

THanks for the info in advance.

pilot1, I haven't experimented very much with my boat and mast like you have, but we have had out H-16 for 31 years and sail often - year round. Our mast is still all aluminum and is still straight up. Every few years I replace the shrouds and forestay. I have Murrays.com make them since Hobie no longer carries the longer shrouds and shorter forestay. We replaced our original Seaway 5-1 main blocks with Harken 6-1 blocks years ago since it's easier to sheet in with the 6-1 advantage.We don't race any more but we often sail with other catamarans on the water and as you know whenever there are two or more catamarans on the water there's a race - just not around marks on a course. I honestly believe that my boat is just as fast and points just as high as the other H-16's with a comptip and the mast raked back. We pitch poled about 25 years ago, but IT WAS MY FAULT, not the boat or the mast. We righted our boat and continued sailing on the same lake, with the same strong wind, with the same crew. With the mast straight up and the boom up higher it's much easier to get to the other side as we get older when coming about.
I often sail singlehanded, with my wife, other family members including four grandkids ages 5-11 yrs., friends and neighbors. The most important thing for me is that I don't think there's anyone else out there that's having any more fun with their boat than I am. We've sailed it to Catalina with an organized group and sailed it all over CA, parts of AZ, and San Felipe, MEX.
It's fun, it's fast, it points high, and it's safe (I check for overhead lines when visiting new places to sail). That's all I really care about and I don't have to experiment any more than that.
If you're going to race I think you should definitely experiment with your boat. Tweek it to make it faster and practice to hone your skills.
I'm glad you started this thread and look forward to reading the comments and experiences of others on this forum.
Richard

Thanks for the reply. Yes, I do race the H16 and that is why I have been playing with the mast. It is tough to get a control factor for testing the "theory" since no wind is the same and the water is never neutral. But I will say this, WHen hiked out on the trap, I will say it feels faster, and the GPS does catch higher speeds when the mast is raked forward BUT you have to fight her to stop from coming into the wind on a heavy pour. Even more so when you are on the trap, with the hull out of the water. I know that I should just set it at the factory specs and leave it, BUT I SWEAR I am getting some more speed out of the boat when I rake it 4 inches forward. I am betting about 2 mph (on the GPS)

pilot1, It's refreshing to see that you're experimenting with your boat and tweeking it in order to go faster, rather than accepting the factory specs and what others may tell you. You're no different than the best athletes and coaches in other sports.
I think the best way to test your boat speed as you make different changes to your boat is to consistantly race against another boat on different points of sail, rather than just relying on your gps in different wind conditions. You make changes to your boat; the other boat makes no changes, and see what works best.
Of course there's a lot more to racing sailboats than just boat speed - rounding marks, starts, combined weight (skipper and crew), positioning of your weight on the boat, speed of tacks, when to tack......
Practice and prepare for different wind conditions.
Wishing you all the best! I'm hoping to read about your many successes in the future.
Richard

I am really surprised at the lack of discussion on this point, as everything I have read contridicts it. Most racers seem to think that mast raked back is faster. What gives?

Unfortunately, I don't have any other Hobie sailers on my part of the lake (that I have seen) to race against, so don't have a way to benchmark it.

Pilot1, keep up the experimentation and THANK YOU FOR SHARING THE RESULTS!!!

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Steve
2017 Hobie 16 "Cayman" sails 114795
1985 & 1973? Hobie 14 "Sea & Ski"

Raking the mast back further is going to move the center of effort aft. and on a 16 this will allow the boat to point higher using the rudders more like boards (kinda) among other reasons...

With lots of rake you will be able to go to weather much 'faster' Downwind performance suffers but not as much as is gained by the ability to go upwind.. Therefore making the boat "faster" on a race course.. even though top speed on a reach might be slightly better with less rake and more power.

If you want to just go fast on a reach, rake it forward as much as you can without having lee helm and being able to control the boat. Controllable is almost always faster though... so don't get carried away.. An occasional pitchpole might be fun.. but it is very 'slow'


Just remember when talking to racers.. "faster" doesn't always mean "speed".. Racing means going weather 'fast' and then downwind fast... The point of sail in which you are seeking speed isn't important to many racers..



At least that is my relative newby understanding of it...


Oh.. and of course you can only rake back as far as your blocks and sails allow... if you can't trim the sails properly.. well....

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www.thehobiewayoflife.com

That is a great summary of the situation, thanks.

I have never sailed in a race, but assuming they make you complete a full 360 degree lap of the circuit, and assuming that upwind legs take much more time than downwind, I can see where getting more speed there makes a bigger impact over the course of a full race.

I can't beleive how much I am learning here.

Thanks,

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Steve
2017 Hobie 16 "Cayman" sails 114795
1985 & 1973? Hobie 14 "Sea & Ski"

OK. I raced today against 3 other 16's and found that on an even drift, winds @ a steady 15, I was walking the other Hobie 16's with the mast forward 2 inches (which lifts the boom off the tramp about 1.5 feet). after a quick pull off and adjusted the mast back to factory specs. We were even keel most of the time. I am thinking this works. The big race this weekend will tell the final story..

And don't forget.. The jib halyard is your fine tuning of that adjustment... Letting it off will depower... and cranking it down will power up.. kinda pulling the mast forward..... although lots of things happen with jib halyard tension... but once you get the rake where you think you like it... Play with that... you can adjust that on the water... just break the main sheet first.

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www.thehobiewayoflife.com

Pilot1,

There is some confusion on the lee vs. weather helm that are going through this thread. If the mast is forward, it moves the center of effort (the theoretical point on the sail where wind force is centered) forward. That puts it ahead of the center of resistance (point where hulls resist sliding sideways) and the result is a turning moment that wants to turn the boat away from the wind, a lee helm. You wrote that the boat wants to turn into the wind with the mast forward, a weather helm. I think you need to look at your rudder rake adjustment which also affects the helm reaction. If a rudder pops up part way the weather helm is very strong. That is a drastic example of the affect of the rudder rake. Raking the mast back should result in a stronger weather helm. A boat with a lee helm is dangerous. There should be a light weather helm so if you let go of the tiller, the boat won't jibe accidentally.

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Howard

hrtsailor, my guess is you know where does spots are on the hobie hull.
You wouldn't mind telling where exactly is the center of resistance or how to calculate it??
maybe even get the hobie hull plans and put them on some software like maxsurf or something to get those points exactly...

I don't see how the nose of the boat would do anything but go down or bury regardless as to mast rake. If I was to stand on a ladder and push forward (aft to bow) on the mast or sails at any point up or down the entire mainsail the nose will always push down. That should remain true based on a forward or aft rake on the mast. How would mast rake prevent burying the hulls? I know it effects how it points but now I am confused even more than I thought I was. Huh?

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Corey
82 H16 project complete

My experience was the same, CorndogCJ. I found that raking the mast, as opposed to not raking it, gives the boat an entirely different attitude. Raking it seemed to move the center of gravity aft. Therefore, if you're sitting in the same position after raking it as you were when it was forward, the stern is going to sit deeper in the water which will submerge the transoms. Submerged transoms can be one of the greatest waste of energy you can acquire while sailing. You may want to examine your boat trim. You and/or your crew should move as far forward, or aft as you need to in order to insure that your hulls are as close to perpendicular to the water as it is safe,(i.e your boat does have a greater propensity to pitchpole going downwind) all other things considered. I have to say that I've pitchpoled a lot less since I've raked my mast and my crew and I are sitting much further forward when beating. Note that the aforementioned comments about increasing rudder rake may also be a concern.

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Happy Sailing,

David

Good luck with that.
Meanwhile, using non-computer techniques (how do you think this stuff was done before people relied on computers?), you can quickly come up with an approximation:

(the bow-down attitude is typical for racing in light/medium air)

I guarantee that these approximations are as accurate as any you will get out of a computer.

However, these are not static problems. A Hobie 16 sailing upwind is highly dynamic. Wave state, weight position, boat speed and a host of other variables make this an essentially unsolvable problem. Kind of like the Heisenberg Uncertainty Principle.

Ultimately, you should set up your boat the way that feels most comfortable for you.

However, when it comes to racing, I'm going to stick with 35+ years of development (with the Aussies kicking our ass) and rake the mast back as far as I can and still sheet in enough to keep the top of the main from twisting to leeward. When I'm two-blocked going to weather, there's less than 6" between the boom and the rear crossbar.

MBounds,

Thanks for putting up the diagram. It clarifies what I was trying to describe.

IturbeR,

I am afraid you guessed wrong. No, I don't know exactly where those points are. I also believe you totally missed the point. I was trying to point out that the raking of the mast forward was contradictory to weather helm when flying a hull and that rudder rake adjustment might be wrong. I have had some experience with weather helm adjustment. I remember the first time I went out in a small sailboat when I was about 7 years old. That was 70 years ago so I have had some sailing experience. For the past 39 years I have sailed a Cape Cod catboat which is notorious for weather helm. For the past 26 years I have also been sailing my Hobie 16. I could probably tell you pretty accurately where the catboat COE and COR are because you can adjust the helm on a beam reach by raising and lowering the swing center board until you neutralize the helm and the boat will sail with hands off the tiller. The COR on the centerboard is pretty easy to estimate and the COE would then be directly above. Going downwind you better have both hands on the tiller and your feet braced on the seat across to withstand the force of the weather helm. As MBounds points out, the Hobie is far more dynamic and subject to a lot of variables. I was sailing Sunday, flying a hull, and took particular notice that I had very little weather helm. My mast is not raked back. By the way, I pretty much gave up with CAD software when I retired from engineering.

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Howard