Hobie Forums
http://www.hobie.com/forums/

upwind performance?
http://www.hobie.com/forums/viewtopic.php?f=32&t=55946
Page 1 of 1

Author:  ptrcksmth [ Tue Sep 08, 2015 6:03 am ]
Post subject:  upwind performance?

Hi all - forum newbie here, but have spent some time reading through past posts...

I'm a sailor looking at getting into kayak sailing, and it seems like upwind performance is the achilles heel of many kayak sailing rigs.

How close to the wind are you able to get regularly with your Hobie sail kit?

For some context: I'm considering an older model Adventure (kayak only) or Revolution 13 or 16, and would plan on using the daggerboard when sailing.

I'm not looking for racing-like performance; if 45 degrees is achievable I'd be happy.

Appreciate your insights!

Author:  Tom Kirkman [ Tue Sep 08, 2015 12:09 pm ]
Post subject:  Re: upwind performance?

Most typical aftermarket kayak sail rigs are downwind only. Hobie kayak sails are true directional sails and allow you to sail upwind to within about 45 to 50 degrees of the true wind. The only place they don't do particularly well, in fact, is DDW. For downwind you want to stay off DDW far enough to keep speed up. This is true of many performance type multi-hull sailing rigs these days.

Author:  Diver_fcd [ Tue Sep 08, 2015 1:01 pm ]
Post subject:  Re: upwind performance?

I agree. The Hobie sail kit will allow you to sail upwind and it really isnt built for DDW. I use it all the time on my Adventure with a daggerboard. Just be prepared for the occasional flip if you are in gusty wind. It's not an Island, it's real kayak sailing.

Author:  ptrcksmth [ Wed Sep 09, 2015 4:02 pm ]
Post subject:  Re: upwind performance?

Thanks guys, very helpful.

I've seen some of the posts about booms & boom battens to improve downwind performance (e.g. viewtopic.php?f=11&t=50246)

Any opinion about Star Sails and their performance relative to the Hobie sail kit on various points of sail?

Emailed a bit w/ Bill who's very helpful - main benefits seem to be that they carry more sail area and have a boom / whisker pole.

P.

Author:  Adamo [ Wed Sep 09, 2015 4:03 pm ]
Post subject:  Re: upwind performance?

I have an early Adventure Island, and you can definitely sail upwind, 45 degrees is doable. I tack when going directly downwind, but I'm planning on adding a whisker line to the aka


Sent from my iPad using Tapatalk

Author:  stobbo [ Thu Sep 10, 2015 5:55 pm ]
Post subject:  Re: upwind performance?

If you use the daggerboard (which means that you will be sailing an Adventure or Revo 16 hull - because these are the only ones thus equipped) you can make good ground upwind.

Exactly how much depends on sea state and wind strength and also the set of the sail (I am going to discount tidal set - because this isn't an issue on lakes and because it is pretty obvious that if the tide is pushing you downwind the apparent performance upwind will be reduced by the amount of the set even though the actual upwind capability may be unaffected - the sailor just needs to factor tide in depending on conditions on the day). For best performance there's a pretty small wind range that these boats can operate in - but they do operate EXACTLY the same as a bigger boat - in ideal wind and sea conditions you will get pretty much the same upwind sailing capability as a larger boat. BUT they sail relatively slowly and they are much more affected by sea state than larger boats. Conditions are rarely ideal for me (always in tidal waters) so I have never had the opportunity to do a compass test on pointing angles in non-tidal water, but the pointing angle ain't half bad in my experience.

Sail set is also important in upwind sailing. This is the point of sail at which there are the largest lateral forces on the mast and sail. The standard Hobie mast, being unstayed, has a tendency to bend considerably when sailing in stronger winds and, while when sailing downwind this is less of an issue, the more you point upwind the greater the forces on the mast and the greater the amount of deflection. Mast deflection affects sail shape and sail shape affects performance. So the farther upwind you point and the stronger the winds in which you do so the more the sail's performance is impacted. There are two solutions: 1. Stay the mast - this is simple, cheap and very effective in improving upwind sailing performance at the expense of added complexity. 2. Get a stiffer mast - I have mad a carbon fibre mast and it dramatically improves sail shape and performance at the expense of being rather more twitchy on the water (less prone to spilling wind as the mast bends) and quite fragile (I am not sure how long it is going to last but it is still going for now!)

I used to have an Outback and I started sailing my Adventure without the daggerboard because they weren't available in the very early days. I also had an Outfitter which I tried to sail. I now have an Oasis that I sail as a schooner. In my experience the upwind sailing performance was/is totally transformed by a daggerboard... in other words: if it is upwind sailing performance you are looking for your only sensible option is the Adventure/Revo 16 with the daggerboard. The other boats simply won't have a snowball's chance in hell of keeping up with you upwind - they can get upwind as people will tell you - using the fins and the waterline for lateral resistance - but factor in the effects of tide, sea state, non-ideal wind conditions and mast bend and the ability to claw ground upwind will be marginal and nothing like a 'proper' sailboat (As said, these kayaks sail just like a 'proper' sailboat - and if you took the daggerboard or keel off a 'proper' sailboat its upwind ability would be considerably reduced.)

Author:  Roadrunner [ Fri Sep 11, 2015 11:50 pm ]
Post subject:  Re: upwind performance?

daft wrote:
So maybe preferable to choose the Hobie inflatable kayak sail kit, which seems to have a nice belly as well as stays already attached to sail.
Using an inflatable sail kit on a standard (non-inflatable) Hobie kayak or PA would be an unfortunate choice since the inflatable mast is too short to fit into the standard mast receiver (lacking with the inflatables). In other words, whereas the standard mast is supported by its through-hull mount, the inflatable mast rests loosely in a shallow pocket and is supported 100% by the stays.

Personally I see the mast flex as a safety valve in gusty winds -- absorbs some of the initial shock by dumping air. The inflatables accomplish the same thing even though the mast is stayed, due to hull flex allowing the stays to "give". For those who want (edit) a stiffer mast regardless there is always the option of putting a stiffener inside the mast tube (not recommended by Hobie).

Author:  fusioneng [ Sat Sep 12, 2015 6:48 am ]
Post subject:  Re: upwind performance?

Keep in mind that everyone at Hobie are sailers first...., and everything they have is designed around their mirage drive system. Every mirage kayak they make is designed carefully from the ground up to be a finely tuned sailing machine (no other kayaks in the world are designed this way). Adding a sail kit to any other kayak is always an awkward deal, and nearly every aftermarket sailkit out there is downwind only (be very selective, when choosing the right kit (many of them are kind of junk in my opinion).

When you add the Hobie sail kit, this turns the Hobie kayak into something entirely different (90% of the Hobie users are not aware of any of this stuff). The Hobie kayak is designed around the mirage drive system, if you remove the mirage drive and pretend to be a laser or sunfish you are losing 90% of your capabilities.
You mentioned sailing up wind, if you pedal lightly while sailing you can easily sail upwind as close as 20 degrees off the wind. The pedaling effort is at a walking pace and anyone should be able to pedal for hours on end with very little effort. While pedaling you are creating forward motion so water streams past the hull and the rudder and keeps the boat from slipping sideways, so a daggerboard is not needed, if not pedaling just pointing the fins down creates an excellent daggerboard for sailing upwind (nothing else is needed on most Hobie kayaks).
If you happen to own an AI/TI, or revolution 16 all have a built in daggerboard or centerboard that makes them even better at kayak sailing vs the other Hobie kayaks, plus there is a huge advantage to the 3 mentioned, they are all very long (longer kayaks are always faster, and always track much better). Because of it's extreme length the TI kayak is the fastest in their fleet (only because of it's length (just simple physics).
You absolutely want to include the furling system in your purchase. We have been kayak sailing our Hobie kayaks since 2007 (many different models), and have literally never taken any of our Hobie kayaks out without a Hobie kayak sail (with a furling kit) strapped to the side of our kayaks. If there is enough wind we throw them up, if it gets too windy we furl them or take the sail down. We are not man vs sea sailing purists (stupidest crap ever in my opinion), we don't pretend we are a sunfish out there (had a sunfish absolutely hated it). We use what is most efficient to get us where we want to go, using what we have available to get the job done, many times we pedal/sail ten hours, then are able to get up and do it again the next day. We could never do anything like that with our paddle yaks (just sayin).
My advise is get a hobie mirage yak (which one doesn't matter they are all good)
We always buy the Hobie sailkit with the boat (they usually give a good discount on accessories).
Absolutely either build your own pvc furler or get the hobie furler (really worth it)
Just go out and start sailing with your mirage drive, start out with your sail mostly furled until you get the balance thing worked out (be prepared to go over a few times, and make sure you know how to get back in the boat (way harder than it looks, and should be practiced)

Now go out and sail/pedal like you stole it. Don't go out there pretending to be a sunfish (thats just plain dumb). The boat was designed from the ground up to pedal/sail, and there is nothing on the market or on anyones drawing boards that can match your capabilities now or into the foreseeable future. Like I said earlier 95% of the Hobie kayak owners out there have no idea just how capable their boat really is (Thanks Hobie)
FE

Author:  bleonard1401 [ Tue Mar 08, 2016 1:08 am ]
Post subject:  Re: upwind performance?

Hate to revive an old thread, but has anyone tried the new spinnaker kit on their AI/TI? It should help with DDW performance.

PS: If any of you guys are into kiteboarding, you can use a small kite and stand on the rail between the daggerboard and the rudder while a buddy steers for some laugh out loud fun. Just make sure to stay aft of the amas and leave the sail on the beach
:-)

Author:  Lead Belly [ Sat Jun 11, 2016 9:57 pm ]
Post subject:  Re: upwind performance?

It has switched to the desktop sailing season in chilly Canberra so I have been looking at my GPS data and headcam videos to try to come up with a reasonably rigorous assessment of the upwind performance (without peddling) of my Hobie Sport kayak that has a boomed sail. Working to windward is by far my favourite point of sail -- indeed, the only reason I ever go voluntarily down wind is so I can go up wind again.

Recently, in winds of around 20 knots on a largish lake (Lake Burley Griffin) with low period waves, my Sport was pointed around 45 degrees off true wind, while the actual sail path after leeway was 55 degrees off true wind, so the angle of leeway was around 10 degrees. (The sail path diagram and a part of the video are shown here in this Forum). These are respectable numbers by sailboat standards. For example, it says in this article Leeway in sailboats: ‘…the rule of thumb is that a sailboat beating to windward will make between 3 and 5 degrees of leeway in a breeze of 7 knots. As the wind increases, so does leeway, until it reaches about 8 degrees in 20 knots’. The longer Hobie sailing kayaks probably point higher and have lower angles of leeway than the Sport, because they are faster and have more bite against leeway. And obviously the daggerboard on the Rev 16 will also be useful in further reducing leeway though I would be surprised if the leeway reduction is more than 1 degree in 7 knots winds or more than 2 to 3 degrees in 20 knot winds.

It should be noted that I deliberately point 4 or 5 degrees lower than close hauled when winds are strong and there are waves. This is the ‘bow down’ technique beloved of Laser sailors (described in more detail here). With my Sport, the bow down technique means faster inline speed; greater water flows over the underwater foils --hull, mirage fins and rudder -- that give lift; delightful balance (as indicated by the lack of weight on the rudder); improved wave handling (drier and less hobby-horsing); and (likely) greater velocity made good (VMG) to the windward target. In my opinion, the bow down technique suits the lift-drag characteristics of Mirage-drive sailing kayaks. The Sport is being sailed in bow down mode in the video. Note how balanced the Sport is when I take my hand off the rudder lever a couple of times.

On another day, on the narrow arm of a smaller lake (Lake Ginninderra) where there were virtually no waves, my Sport in close haul mode pointed around 42 degrees off true wind direction in fresh winds and tracked at a little over 45 degrees. (The sail path diagram is shown here in this Forum but no video is available). This implies the estimated angle of leeway was only 3 or 4 degrees and illustrates how important waves are as a determinant of leeway and, hence, upwind performance. But it felt like the Sport was towing a bucket -- ’close hauled’ in a Sport should be called ‘close haulage’.

Tacking ability is also important in upwind performance, particularly when you are in narrow waterways or trying to work the knocks and lifts that come with wind gusts. You can see from the video that on a windy day with waves, my Sport (9’7” long) tacked through 90 degrees in well less than 10 seconds with a bit of forward momentum left. Certainly good enough for this recreational sailor! Maybe tacking is a little slower with the longer Hobie kayaks. Be great if there are some sailing advantages to being the shortest kayak in the Hobie list!

So I reckon that Hobie sailing kayaks -- with appropriate sailing techniques --have pretty reasonable upwind performances, even without daggerboards.

Author:  fusioneng [ Sun Jun 12, 2016 6:06 am ]
Post subject:  Re: upwind performance?

I dunno, I must sail upwind differently from most others. One reason I always add jibs to all my boats is so I can point much higher upwind.

The first jib I added was on our Oasis kayak because the boat was rather large for the standard Hobie kayak sail and Hobie didn't offer anything else. My wife kayak sailing side by side with me on her revo 13 literally walked away from me, and would come back circling me and taunting me to keep up (totally humiliating). In the area we live 85% of our sailing is typically upwind because of the geography. To remedy my situation I added a small jib to my Oasis and developed a technique for sailing super close hauled up wind that I still use today (10 yrs later). It's a little different but it allowed me to keep up with the wife upwind. While she was tacking back and forth like crazy, I pull both my mainsail and my jib as tight as possible (pointing directly into the wind). I then start peddling to get forward motion. Once I'm moving I begin to turn offwind till the sails catch wind. This typically ends up around 20-25 degrees off the wind. As long as I keep peddling I can make headway upwind even in higher winds. Granted my forward speed isn't nearly as fast as my wife zig zagging back and forth on her tacks, but it gets us from point A to point B at about the same time (my VMG is much better).

Yea I have to peddle 100% of the time (if I don't peddle the boat stalls and stops).
In 2010 we traded in the Oasis for our current TI and I continue to use the exact same technique probably 90% of the time whenever I'm out and sailing upwind.

I have no idea whatsoever if this technique works without a jib mounted on a boat because since then I have fitted every boat I've owned with jibs and have never tried to sail without a jib on the boats of one type or another (many different designs).

Of course I'm no hard core man vs sea hard core sailer, and the reason I started buying Hobies in the first place is for their mirage pedal drives. My pedal boats are my exercise program and I always pedal 100% of the time I'm on the water, usually at a 40-50 cpm cadence (walking pace), which I can maintain up to around ten hrs. I then sail to the best of my ability to increase my speed and range using whatever wind I have available the best way I know how. I'm pretty sure this is different techniques from everyone else for different reasons. The areas we live in are vast (SWF, and the keys), our specific purpose for owning the boat is to get from point A to point B as quickly as possible so we can get out of the stinking hot boat in the hot Florida sun so we can anchor then dive, snorkel, and spearfish in the water (where it's much cooler).

Even when we meetup with our power our friends we typically meet at some sand bar and everyone sits in the water and hanging out.

It's funny there are a gizzilian sunfish and lasers around here, I don't recall ever seeing any more than a mile or so from launch, typically just zigging back and forth or sailing around bouys. I almost never see those types of boats offshore, or at the sandbars, actually I've never seen anyone fishing from one either. That's their thing, and ours is our thing, and our paths seldom cross. Actually we launch near a sail boat club, and considered joining, they were very friendly toward us until they found out we were kayakers (not sailers), and they got very hostile toward us so we elected not to join (true story).

Hey if anyone tries this upwind method (without a jib), let me know if it works. Of course you would have to pry my jibs out of my dead hands, because I've grown so accustomed to using them, I honestly have no clue if my jibs improve my performance or not, because I've never gone out without mine so I don't know any different. I guess I feel differently from everyone else with TI's, I consider my jibs, spinnakers, and supplimental motors as the tools in my toolbox to get me from point A to point B as quickly as possible so I can get out of the boat and into the water where it's cool, spending as little time as possible actually on the boat, (probably direct opposite of everyone else lol). Our boat is yellow and in florida sitting in the boat I always feel like I'm in a frying pan and I'm the yoke (lol).
Our TI is specially configured and designed so my best performance is 15 to 20 degrees off the wind upwind, (because of the geography of the area we are in this configuratio 85% of the time) and the absolute worst point of sail is a reach so I avoid sailing on a reach like the plague, that's just the way the boat is designed.

Since pretty much everyone only talks about 45 to 55 degrees off the wind upwind, it sounds like my technique doesn't work on other boats, or everyone just loves to tack (I don't tack ever lol).
That's our story and were sticking to it.
Signed.
"Really bad sailer" FE

Author:  stobbo [ Fri Jun 24, 2016 2:54 am ]
Post subject:  Re: upwind performance?

I am not sure why having a sail with a big belly is a good thing.

The sailing theory goes: more belly in lighter winds, flatter in stronger winds. When sailing downwind the apparent wind is less than when sailing upwind but you can still get strong winds sailing downwind and light wind sailing upwind. On a boat with a boom you can stretch the sail along the boom and mast to make it flatter and you can reduce the stretch and bend the mast (on some boats) to make the sail fuller. And these adjustments have a noticeable effect on sail performance - which is why yacht racing crews have a sail trimmer.

The problem on the stock Hobie rig is not that the sail lacks a boom per Se, but that the mast bends like a noodle in anything more than a light breeze, and the bend increases as pressure in the sail increases (I.e. Upwind) to the point that the sail loses all shape and performance. In practical terms for me this means that, just as the wind pipes up enough to provide enjoyable/challenging sailing, the sail becomes a potato sack and the sailing performance from the rig falls away to almost useless, not to mention difficult to use, because as the sail loses shape, so the centre of effort in the sail starts moving around making the rig unstable.

The answer is to make the mast stiffer so that it doesn't bend, thus allowing the sail to keep the shape that was sewn into it by the sailmaker as much as possible.

On the Hobie, the sail will naturally flatten somewhat as you haul the sheet in tight to sail upwind, and it will naturally become more full as you ease the sheet to sail downwind. So in fact a boomless rig does lend itself to 'auto trimming' on different points of sail just by dint of the way the sail is set up without a boom.

You can make the mast bend less by supporting it with stays or you can swap the aluminium mast for a stiffer carbon fibre tube-I have done both and they both make a huge difference to sailing performance; stays are cheap to make up and allow you to support a jib as well but reduce the furling ability and can be less easy to use; a stiffer cf mast is light and very easy to use but would have to be really stiff if you were to fly a jib as well and carbon fibre is rather expensive and fragile.

The decision and choice are yours but either way you will notice a marked improvement in sailing performance on most points of sail (except perhaps dead downwind) especially in stronger breezes if my experience is anything to go by.

Author:  fusioneng [ Fri Jun 24, 2016 11:25 am ]
Post subject:  Re: upwind performance?

Obviously I don't think like anyone else, and am about as far from a sailing purist as you can possibly be (man vs sea and all that rot). Like I have said before I used to have a Sunfish and absolutely hated it, all you could do was zig zag in front of the docks a mile or two from launch, only in certain conditions and that's it (gets old quickly). Who gives a care if my personal ability sailing the exact same boat as everyone elses (a 60 yr old design) is better than someone else's to sail around little bouys.
I have still yet to see anyone fishing from a sunfish or laser, or seen any similar type boats parked on the many sand bars just hanging out in this area for the day (the thing to do around here and the keys to get out of the crazy hot sun). However people do use their Hobiecats ( I'm a little jelous there).

I much prefer to use my mind and new technology to cheat by any means possible to achieve getting from point A to point B as quickly as possible with as little physical effort as possible and that's it. I am no athlete and never will be, but on the other hand I am not the type to scream around on a jetski, or a 75mph gofast boat, (though I am a motorhead and former powerboat racer/builder (hydroplanes), but that was many yrs ago). We used to have a Sea Ray Powerboat and it almost broke us keeping it up (powerboats are huge moneypits in Florida).

The point I'm trying to make is forget about pure sailing the old fashion way (2000 yrs old tech), the way monohulls, lasers, and sunfish do it, erase that old obsolete stuff from your mind. What you have is much more powerful than any of that stuff, it all comes right out of the box from Hobie with any of their mirage kayaks when applied properly with the key point being 'not to try to assimilate or emulate all the old crap out there that hasn't changed much in the last 2000 yrs'.

Here is a video of my TI sailing in 8mph winds sailing almost directly upwind around 15 degrees off the wind at faster than windspeed, then later on (around 6.5 minutes in) sailing downwind faster than the wind speed, all exploiting what we call apparent wind. ( Any Hobie Mirage kayak can do this)
Watch the video then come back, let me explain how to do it with any mirage kayak (which mirage kayak model just doesn't matter, all have this capability designed in right from the factory).
https://www.youtube.com/watch?v=eJ9Y7gBo8-Y


I understand this is a little hard to grasp, and goes against the grain of what everyone assumes and understands. This discrete video published in Feb 2010 by giz magazine is where it all began. Most boring video ever created but it hints at all the possibilities, get some popcorn and open your mind:
https://www.youtube.com/watch?v=241QmxFcbuc



By combining all three power sources and exploiting all at the same time (which they don't even mention), true Tri-brid propulsion is not only possible but is now a reality.
The TI is a very large boat, and I am no athlete by any means, so a small amount of supplimental propulsion is required via either hybrid outboards or electric/solar (just doesn't matter which you use).

With two fit peddlers the supplimental propulsion can be eliminated completely, the downside is we as humans run out of energy in a mile or so (thus the need for supplimental propulsion at this time).
Obviously I'm into human power, and always pedal my Mirage boats 100% of the time at a sustainable pace ( up to ten hrs at a time).
A perfect example of this (if anyone wants to try it), would be to take a revo 13 or revo 16 (only as examples, actually all Hobie Mirage kayaks should be able to do this). Add either a rudder mounted Evolve, or a trolling motor of your choice. Point your kayak directly into the wind, pull the Hobie kayak sail tight and start peddling, and apply a little supplimental propulsion. Once your speed is up to around 4 mph turn off the wind slightly. Your sail should fill in and start utilizing the apparent wind created by your forward motion combined with whatever natural wind is available to provide additional propulsion (in effect doubling the wind over your sail). By doing so you can easily sail 20-25 degrees off the wind at a pretty good speed giving you the best VMG possible. You should be able to sail a revo using this method at 5-6 mph upwind. Obviously if you eliminate the supplimental propulsion aspect, then you have to pedal way harder to get the same effect ( I don't want to do that, just sayin).
This is an artificial sailing stance, meaning if you stop peddling the boat will just point into the wind and stall (that's exactly what all mine do). However by careful control of your rudder, and not allowing the boat to point too far off the wind with full sail out (capsize results), you can point up wind on a Hobie sailing kayak into some pretty significant winds. Since the boat is pointing almost into the wind, the heeling moment on the boat is minimal (thats the force trying it's best to tip you over), and also if their are gusts, you have time to react and adjust without having to go swimming.
Same exact concepts also work on downwind (as shown at 6.5 minutes into the video). By applying supplimental propulsion and peddling you can actually tack down wind the same as you tack upwind by exploiting the apparent wind you generated by your forward motion, then re-directing the natural wind to power your sail. At this point you are actually sailing faster than the wind itself. Obviously you can't point downwind as close as you can upwind, but you can pretty safely go downwind 35-45 degrees off the wind with enough forward motion to be able to re-direct some of the wind around your sail (as long as you are sailing faster than the natural wind, or somewhere reasonably close). Your sail in this circumstance will not be the ever familiar taco shape we all recognize when trying to sail downwind (which is pretty useless BTW). Your sail configuration will more resemble a close reach or beam reach sailing (just be careful when jibing, that can become tricky as seen 6.5 minutes into the video).

An added benefit to sailing this way is all the power calculation associated with the Evolve and other electric configurations assume your motor is providing 100% of your propulsion needs. When pedal sailing with supplimental propulsion (tribrid sailing), your evolve/electrics/solar only needs to provide 1/3 of your propulsion needs (tripling your battery range (in theory anyway, pretty dependent on how hard you really want to peddle, and how long you can sustain a certain peddling pace, I for one am not up for that), I prefer brains over brawn ( lol).

Anyone who wants to try all this stuff out can try it all prior to adding any supplimental propulsion device (Evolve, etc) just by peddling harder than normal (pedal power would be 2/3 of your propulsion needs, sail power 1/3), however if your like me I can only sustain that pace for a mile or so then I'm out of gas (thus the need for supplimental propulsion).

On our TI with 2 strong peddlers we can maintain everything you see in the video (and the 30-40 other videos I have posted) without needing the Hybrid engines at all, but we get pretty winded in a couple miles. Everything described can also be done on a regular Hobie mirage kayak as well. We never bothered with outriggers kayak sailing (outriggers are training wheels for kayak sailing IMO ( lol)).

Of course if you get winded, you can always resort back to the old fashion way of sailing, none of those capabilities are ever compromised. In my opinion on a Hobie Mirage kayak I would much prefer a Torqeedo 403 on a rear ball mount over Hobies Evolve, this way you don't lose your mirage drive capabilities, or experience the extra drag created by the evolve mounted to the rudder. (basically they are both the exact same unit (manufactured by Torqeedo)), and pretty close to the same price). The Torqeedo 403 can also be adapted for use on any kayak (not just Hobies)

I've been sailing Hobie kayaks (all different models) for about ten yrs now using these techniques. To the best of my knowledge there is no other boat on the planet that can do what these Mirage kayaks can do (bar none).
Try it you'll like it... Any existing Hobie Kayak sailer with a sail kit can try all this methodology out without spending a dime (the capabilities are designed into the boat), well for short distances anyway (lol).
Hope this helps
FE

Sorry for the long rambling response.

Author:  wthoms2000 [ Sat Jun 25, 2016 6:36 am ]
Post subject:  Re: upwind performance?

This helps:

Image

Image

Image

Old Hobie 16 rudder.

Author:  fusioneng [ Mon Jun 27, 2016 6:47 am ]
Post subject:  Re: upwind performance?

Daft:
I've seen videos of this many yrs ago, all these guys have it all wrong, they are trying to use a single means of propulsion (natural wind) to propel their boat. As you can see the guy is just crawling along at maybe 1-2mph (whats the point nobody wants to go that slow. The guy is sitting on the boat doing nothing, if he had a mirage drive (or two) that produces some forward motion (3-5 mph) by moderate peddling, that added to whatever natural wind is coming at the boat would make the apparent wind driving his windmill 10 mph (assuming 5mph wind and peddling at 5mph). Now his underwater prop optimally pitched with a power range to propel the boat from zero to 5mph, the energy is wasted. If he pitches his prop so the optimum power range were lets say 5-10 mph, then the prop can add propulsion. Of course if the boat were sitting still it would take more force than available to turn the underwater propeller (thats all assumed).

Now what if there was some way to improve, accelerate, and focus the air blowing onto the windmill. This can be easily done with a wing. Basically what the wing does is it takes any wind passing over it (in this case 5mph from your forward peddling motion, plus the 5mph natural wind coming at you. That natural wind can be coming from any direction in front of you from about 5-10 degrees up to around 70 degrees, then aligns, redirects, and accelerates that wind straight back into the windmill, in essence making the windmill work harder, where without the wing or your forward motion it would be doing nothing.
All this stuff added together is called tri-bred propulsion.

By combining multiple sources of propulsion with each source only having to provide a small percentage of your overall propulsion needs you can do amazing things.
Using the guys windmill boat in the video as an example. Lets say he adds a mirage drive into the mix and he is very athletic, and he can pedal that little cat 8mph for a mile or so until his legs turn to rubber (just the boat, pretend the windmill is removed or feathered, and there is no wind or current). Even if he had a big TI most of us can pedal up to those speeds for short distances). When going 8 mph if you add that to whatever natural wind you are sailng into, the wind blowing onto your face lets say 8 plus 8 mph equals 16 mph wind blowing into your face. Now lets organize and amplify that wind (with a wing) so the focused wind blowing at the windmill is 18-20 mph. That wimpy little windmill is now generating some serious horsepower, and is sufficient to drive an over pitched propeller. Of course if you stop peddling everything comes to a screaching halt (because the force to drive the underwater prop exceeds the hp output of the windmill.
Even my boat cannot sail directly into the wind, in order to force my wing into it's assymetric form I have to direct the wind more from one side or the other, typically ten degrees will do it (less in higher winds).
When there is zero natural wind (almost never) I have to tack on curved paths in order to maky my wing flip to it's assymetric shape (creating lift). However the amount of additional propulsion and wind amplification the wing provides is miniscule at that point (I basically have to have some natural wind (doesn't need to be a lot)).
It's all very interesting stuff, but has very little to do with actual sailing which is a different world alltogether. Yea my boat has sails, but I don't use them for that purpose. Of course I can always revert back to old fashion sailing at any time, but when in that mode all the old rules still apply, (ie... Can't point much closer than 45-50 degrees off the wind, and the boat typically performs around .6 of windspeed (no different from any other sailboat).
Sorry about the long dribble it just frustrates me to no end that people are so stuck on ancient tech (lol).
FE

Page 1 of 1 All times are UTC - 8 hours [ DST ]
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/