Making revolution more competitive with performance kayaks

I realize this won't interest most folks, but I recently found that my revo 16 was slow compared to the paddle kayaks I go with. Yes, I do paddle half the time due to shallow back water in southern fl.

Having built a number of airplanes and tweaked them to be more efficient, I looked at five holes in the bottom of my 16 plus three other shallow ones, all making for less glide and less speed. So you may ask why I care, well I am male and had to ask some 62 year old women to slow down for me and yes I am still strong but in my seventy's.

First I sprayed parting agent on the pedal opening and foamed in all the gaps around the black plug. Removed this, applied bondo bringing to plug even with the bottom, sanding the corners and upholstering it in vinyl. This is a tight fit and I had to put an eye and rope to jerk it out, it is that tight. Now I have an even bottom, no turmoil there, and yes it still drains as it is not that tight.

The two drain holes beneath the seat I screwed in flapper valves flush with the hull. I think, this would work with the wheel holes. But by that time, I cut aluminum tube, inserted bondo and made a flush plug for each hole, again no turmoil, just smooth surface like a real kayak. The other few shallow holes, I saw were flush on my wife's revolution and now so is mine.

Now to my wife's revolution. I know the seat is more to the rear CG which is good in waves, not so good in keeping up in a group paddling. A small weight in the bow helped here as weighing 200 lbs, it wallowed going into strong tides.

Now, did all this help. I will not know until this Friday when I will discover if these old ladies beat me again. I did try some tests which is unscientific due to breezes and differing tides in front of my home. But over all, I see about one half an hour increase in relaxed paddling with noticeably better glide between strokes. I feel with some simple solutions, this may make the kayak far more versatile without having to buy two for multiple purposes. I also found it odd, I could not find any others on line even considering this. I am sure that hobie with a few pennies could produce flush flappers over all the holes and surely make a form fitting plug, not all of us are fisherman, some like me are older, damaged physically and need all the help we can get.

Some pics would be good sailormon!
Roadrunner has posted his streamlining mods over the years. He reports packing tape over the holes makes a difference viewtopic.php?f=11&t=37403&p=152388
I like his mod to the drivewell plug

he reported about on p9,10 here viewtopic.php?f=71&t=33359

I like the way the plug looks here. I did a quick crude fix and stretched vinyl over and sewed it on. Both kayaks for a few dollars. Considered tape, but wanted a more lasting solution.

Will take pictures with my ipad and sent along tomorrow. Good to know others were concerned.

Be sure to run them up wind in chop... that is one area the drive excels over paddles.

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

Make it more competitive? Yes, put back the original seat like it was and add some rocker and give some hard chines in the rear so the ass end stops popping out when going fast with the drive with wind at our back and following sea.

If you are comparing your speed while paddling then yes you are likely to find that a big heavy polyethylene sit on top that is designed primarily for mirage drive propulsion is not going to be much of a match for a kayak that has been designed specifically for paddling performance (and is probably a lot lighter/narrower/sleeker etc to boot).

HOWEVER...

...get that same Mirage Drive kayak into deeper water where the Mirage Drive can do what it is meant to do and (unless YOUR legs are substantially skinnier/weaker than THEIR arms) you will find that over any reasonable distance or against any sort of headwind/tide or chop you will beat the paddlers hands down.

I am speculating but I reckon that the reason that most people on these forums are not so concerned about fairing their hulls completely smooth is that the Mirage Drive is just so much more powerful than a paddle, and the MD kayaks are therefore so much longer-legged than your average paddleyak with a recreational paddler, that it hardly seems worth the effort... certainly seems that way to me. That said, like you and Roadrunner I have had a go at improving the fit of the drivewell plug but I have done that to see if I can improve the performance under sail (I usually pull the drive when sailing): I so rarely paddle that it just doesn't feature on my agenda except as an emergency get-you-home measure.

I hate to tell you this but you may be doomed here. Hobies kayaks are designed pretty much around the mirage drive. If your two hundred lbs and going against a 100 lb female expert paddler on say an Epic V7 Surfski on flat water they will outpace you every time. It has everything to do with boat length (longer is always faster), and boat width (narrower is always faster). The Epic weighs 50 lbs and yours fully rigged weighs around 92 lbs.
we are long time canoe/kayakers and now run a Tandem Island (without the sails and ama's when kayaking) though we have owned quite a few other Hobie kayaks as well.

There are several classifications of kayaks out there with the most common being recreational kayaks ( typically these are the type that most people rent). Your boat should be able to out perform and outdistance most of that class of kayaks via the mirage drive which only takes 1/2 the energy to use vs regular paddling on these types of entry level boats. Once people understand and really get into kayaking they typically step up to more performance orientated boats like surfski's and sea kayaks. These better sleaker lighter boats can get very expensive. We spent a week in a cabin next door to a family who had a pair of Hawawiian proas that were 22ft and 24 ft long and maybe 18 inches wide, I don't think either boat weighed more than 30 lbs, I'm also pretty sure either boat cost double what my TI cost. I'm a pretty good kayaker and really strong on the mirage drives with very strong legs from going out weekly for many years. We both launched every morning about the same time and they left me in the dust every day, litterally out of site in under 30 minutes every day (pretty humiliating). Turns out they were world class pro's who travel around the world doing this full time, and half my age with probably triple my athletic ability. We got to know each other and laughed about it by the end of the week. It was a fun experience.
We also live in south florida and go in a lot of shallow water, however I would never remove my mirage drives. If you practice at it you can learn to shallow pedal almost as fast as regular pedaling. You can easily pedal through 6-8 inches of water all day if needed. What I do is raise the rudder and shallow peddle for propulsion (uses way less energy vs paddling and you can easily pedal all day long once you get your legs built up).
For steering you use your paddle with occational swipes thru for added propulsion and steering. If you are using the Hobie supplied paddle you might want to look into a little higher quality paddle they are not cheap by any stretch of the imagination but well worth the investment. Have a very experienced paddler or a kayak outfitter advise what would work best for you.
If you don't have the Turbo fins get them, and if you have the older mirage drives upgrade them to the new glide drives (hobie sells an upgrade kit).

I suspect the reason most of us don't worry about the scupper holes, and a few scratches on the bottom is those darn mirage drives are so darn efficient, those little things mean very little.

Also paddling itself is all technique, get training and advise from an experienced paddler, way more too it than it appears. You still may not be able to keep up with a long skinny surfski like the Epic, but a steady easy walking pace type cadence with your mirage drive (as your main propulsion), and using your paddle lightly for supplimental propulsion and steering (rudder up in the shallows) you should with practice be able to hold your own. Remember to shallow pedal in the shallows, and pull your mirage drive occasionally to clear the weeds off.
Hope this helps
FE

You are up against the laws of hydrodynamics that imply hull speed is an increasing function of length at the water line (LWL) and a decreasing function of displacement.

Based on my perhaps naïve use of the equations reported at http://potter-yachters.org/manyways/hullspeed/, the difference alone between the hull weights of a 16’ sea kayak (50lb) and a rigged Rev 16 (92lb) means the sea kayak will be 430 metres (475 yards) ahead of Rev 16 after an hour. If the sea kayak is 2’ longer than the Rev 16 but still the same 50lb weight (for ease of comparison), the sea kayak will be 940 metres (1020 yards) ahead after an hour. (The calculations assume everything else is equal, including sailor's weight of 175lb, and a cruising speed that is 60 per cent of calculated hull speed).

The design of sea kayaks – touring kayaks that are long and narrow - represents a trade-off in favour of speed at the expense of stability. Eskimo roll anyone? Compared to sea kayaks, the design of Hobie mirage kayaks is (to me) a sacrifice of speed in favour of the higher displacement that is necessary to deliver both stability and the structural strength required to mount the vantage seat and the mirage drive.

Best strategy is to get your competitors to carry additional weight as far aft as possible as this may reduce LWL and does raise displacement.

Sounds like a good idea to cover over hull holes in your Rev 16, but short of flagrantly disobeying the laws of hydrodynamics, I don’t think you are going to be able to keep up with those women…..[my wife’s addition] ‘Get over it ’.

Yea I didn't even mention that part, that guy let me sit in his Kamanu composites kayak. The thing was 18" wide 24 ft long and the whole boat (carbon fiber) was I think he said was 28-30 lbs. It was a pro boat, no different from sitting on a log and no way I could even stay upright let alone kayak in open ocean (where we went every day). The funny thing is he had an AMA (proa) for each boat but never used them all the time we were there (he kept them in a bag in the back of his suv). I think I remember him saying one boat cost him around $7 grand and the dual was around $10k.
I think there is something significant about the length/width ratio of the boat when it comes to hull speed. Anything with a ratio of 16/1 has no hull speed limitations of any kind (no wave is created). Pretty much all cats have a ratio of greater than 8/1, this is why cats are so fast, the max hull speed becomes a soft number on anything with a greater than 8/1 ratio. Another thing that factors in here is gender. Women are much better physically equipped for endurance. I'm 230 lbs in my mid 60's, and am a pretty strong paddler. An experienced 100 lb skilled female paddler in a properly equipped Surfski would leave me in the dust as if I were standing still. Like your wife is telling you , get over it, you can't win (lol), it's the physics, not your boat.
Hope this helps
FE

Agree 100% with this. Hobies (and lots of other SOT kayaks) are no match for a normal seakayak with an ordinary paddler. But when using the Mirage Drive in a Revo 16, that is something completely different! The glide is of course not so good in the Revo 16 compared to a normal seakayak, so you burn more energi per mile at the same speed in a Revo 16. I can hold a speed at 8,5 km/h for at least one hour in a Revo 16. For a normal person in a normal seakayak it could be hard to beat me. Depends a lot on their skills in paddle technic, their stamina and of course the seakayak.

I own both a Adventure Island (use it a lot in Adventure mode, single hull) and an Epic V7. The Epic V7 is by far not the fastest Epic surfski but has a good glide and with good stamina and good paddle technic, I have heard that 10 km/h is doable for longer periods. I am still faster (in one hour) with the Adventure even if top speed is lower. I am now working to hold 8 km/h for one hour with the Epic V7.
And in time, I will do it!

br
thomas

Kal-D-pal:
I think you missed one key point in the OP's posting. He removed his mirage mirage drive and plugged the hole, and is trying to paddle with no mirage drive. We have a TI which has an 8/1 length to width ratio vs the Revo 16 with a 6/1 ratio. I'm pretty certain paddling wise (with no mirage) the TI kayak (IMO) is fastest in Hobies fleet (specifically because of it's L/W), but no match (paddling) against even a low end surfski like the Epic K7 (the only reason I mentioned that particular boat is because it's middle of the road and fairly common and inexpensive, and most people are aware of it and it's capabilities (lots of those around here)), of course there are way better boats out there.

What I was trying to accomplish is to convince him to put his mirage drive back in, learn how to shallow peddle (what most of us have to do down here in S Florida and the keys in the really shallow waters without our rudders). And to make sure he is using Hobies latest mirage drive tech (which is awesome). I tried to convince him to get a really good paddle (not so much the Hobie paddle which is good for pushing off docks) and learn how to paddle for most efficiency with least effort while using his mirage drive for primary propulsion.
By his discription the ladies he is going out with are pretty seasoned paddlers and I'm pretty certain they are not running 14 ft Wilderness rental boats. He's still going to get spanked badly, but should be able to retain his humility (lol).
Keep in mind 95% of all Hobie owners never use their paddles at all ( the Hobie paddle is strictly ornamental (lol)).
I'm sure he would greatly appreciate any additional advice he can get.
FE

@ fusioneng
No I don't think I missed anything. Maybe I was unclear, my english could be better. My point was that stobbo was spot on: you can't beat ANY seakayaks when using paddle in a Hobie kayak. But when you are using the Mirage Drive you are suddenly very competitiv even if you can't beat everyone. I know because I have participated in 3 very long races against surfskis and seakayaks. I was the only pedal driven kayak. I beat a lot, even some surfskis, but against the best paddlers I have ZERO chance. They were very long distance ahead of me.

About me in the Epic V7, still no match for me in the Adventure (pedal driven) if we are talking about an one hour race.
I don't have the paddle technic to keep enought speed (without draining my energy) to keep up with myself in an Adventure.

The Adventure / Revo 16 is a fast kayak even compared to seakayaks. But NOT with a paddle!

best regards
thomas

Thomas:
Great answer
FE

The list is already impressive:

• Plug holes

• Run them up wind into a chop

• Change seat back to original, add rocker and hard chines (probably suggested as longer term improvements)

• Improve paddle technique

• Shallow pedal as well as paddle

• Lose weight (change gender?)

• Ask them to carry extra weight (picnic hampers, water etc.)

• Switch to deeper water where mirage drive can be fully employed

• Keep to longer distances so that you can play to the endurance advantages of mirage drive

Holy women in seakayaks, Roadrunner, what do we do now!?

Hey it seemed to work fur Bruce Jenner (lol)