Ducati Scott, the prototype Blade F16 with smaller beams (80x2 mm alu) then the VWM Blades ever had flexed ONLY 45 mm in the standardized test stand. The standard Taipan 4.9 (both AHPC and homemade timber) flexed 64 mm. My own widened boat (again with less rigid beams then the prototype Blade) flexed 65 mm (AHPC mast as mainbeam and 80x2 rearbeam). I seem to recall an early 2006 VWM blade F16 standardized flexing measurement of 50 mm it uses exactly the same beams and hull setup as the 2005 version. The newer VWM Blade F16's as delivered by the EU agent flex less then 25 mm in the same test stand (2 times 90x2 beams).

I have no standardized flexing tests for the Stealths but these are most definately stiffer then my own boat and that of a fellow owner (VWM Blade). Stealth has always been rather stiff platforms in my opinion.

Again I note that all these measurements were executed using the exact same test procedure, so they are directly comparable.

I find it really hard to believe the 80 mm flexing measurement that you refer too.

I do note that such a claim is often used when describing the Viper F16, but I question the dependency of it. If anything, the Viper should be compare to the specs of the currently available models (not of passed introduction batch models) and all of these are significantly stiffer then your quote measurement suggests. The other builders certainly have not been idle over the last 4 years !

I do grant the Viper F16 appears to have a very stiff platform if the 137 kg prototype present at the 2007 Global Challenge is any indication. Yet, the competition is a whole closer then you make them out to be.

As an engineer and F16 sailor I like my own platform to be stiffer (65 mm flexing), but I see absolutely no benefits beyond 25 mm flexing. While sailing I don't notice any hull flexing on my current boat although I'm convinced that reducing it by halve (35 or less) will make it feel slightly better in severe chop. I feel the Viper should be placed in the latter group, together will all other F16's sold new or of max 2 years age.

Wouter

I have only had the one sail on the Viper. My experience was, it was noticeably heavier whilst sailing and pulling up the beach, even with the eurotrax wheels, than the Blades I have sailed, however much lighter than the Yvonne I crewed on last year <img src="http://www.catsailor.com/forums/images/graemlins/blush.gif" alt="" />. I don't know how the weight of the hulls of the viper compare to the the other F16's, but the foils, beams and rudder stocks are much heavier than the blades. I would imagine the rig would be the same as all the other boats. At a guess, I think at least 5 kilograms could be saved there.

When we popped the kite we stuffed the bows past the mainbeam in about 6 knots. To the vipers credit it did just pop back up, but it was very slow. That's when I very quickly learnt that the viper needs you to get the crew weight right back.

In all honesty this will be same on any F16 design when not fitted with T-foils and even then ... !

The 16's are weight sensitive with respect to the ideal (waterline) trim. That is just a given on LIGHTWEIGHT and SHORT hulled platform. There is only so much you can do with increasing bow height and volume DISTRIBUTION. Afterall, if the crew weights combined significantly more then the overall weight of the boat then crew position will be very important. Especially when the sail forces are significantly larger in size then boat weight as well. All these things combined make the sail trim and crew weight placement the main axis around which the whole boat behaves. The boat (hull design) itself is only a rather small influence factor (trim tab) on of this, much more so then on larger and significantly heavier designs like the F18 and F20's/Tornado's.

Personally I regard this as a mixed bag. I like the very direct responsiveness of all F16's and find F18's and larger boats sluggish by comparison. On the negative side it means you have to perfect your downwind spinnaker technique in shot waves alot further than on the other boats. You get the good with the bad and the bad with the good. There is no magical solution to this, even the T-foils let go at some point.

Last time my Skipper and I had to beam reach with the kite up with tried a new approach. The seas were too confused to put one of use on the trapeze behind the rearbeam (and in footstrap). So the Skipper slid down the trampoline with his rear against the rearbeam and I (heavier of the two) sat against the rearbeam and on the outer gunwhale of the hull. Thus we were both with our rear ends against the rearbeam. The boat would lift a little sooner, but that makes the Blade only faster. We survived about a 40 minutes of higher course spi sailing in confused seas and multiple deep dives. We had very good speed. Coordination between crew and skipper was also very important with me regulary calling the loads on the spisheet and the skipper adjusting course just prior to the main gust hitting.

I really do like the team work on an F16 boat. Good sailing skills and honed team work make all the difference; so much more then being near the optimal crew weigth.

Wouter

I agree. Maybe I should have written "that's when I very quickly learnt that F16's need you to get the crew weight right back." My point was I don't think the Viper is very different in this regard, despite the talk of higher hull volume compared to other designs.

JJ,
I am responding to your original post regarding recreational sailing of Blade F 16. Although I had hoped to race my Blade there just aren't enough other boats in the neighborhood. (Maybe I've not looked hard enough). I sail in conditions where the wind shifts and gusts, always, and sandy beaches are 200 miles away. Hull fragility became an issue. I had major problems with one hull and ultimately I ground off 0.030 inch of gel coat and applied 6 oz s-glass over the entire bottom with premium no blush epoxy. I painted that with Brightside white polyurethane. So far it is one tough son of a gun and I don't think I added more than 5 pounds.
When I look back on my purchase I realize I was thinking recreationally as I believe the boat to be strong, can be effectively de powered in strong wind and sail fast rather than the survival sailing I use to do on the H16. I bought the Blade without jib because I sail alone and the gusty conditions are more negotiable if I only have one sail to dump air out of. As Gilo mentioned earlier, get the spin, it is so much fun. You'll find yourself sailing up so as to set the spinnaker and sail down. I think the spin is probably more fun recreationally than competitively?
Regards,

Stretch
Yep we've all got prebent poles to. We use Dyneema rope so no stretch there. But if you sail in decent breeze you'll have a fair bit of compression on the mast i.e. the side stay will go loose by a bit and that allows more slack in things. Even though we sail with almost 0 downhaul downhill, everything gives a little.

Having people do things in slightly different ways, makes racing interesting!

Weight
All up... good to go. You take away the F18 boards/rudders they had originally and that saves bulk! After the pre-production models, the builder got a lot more practice and the weights stabilised.

Pulling up the beach
Taipan is easy because it feels tiny after the Viper!

Hi Wouter
Thanks for the accuracy rating.

Can sum it up by saying that in terms of deflection from 'most flexible' to 'least flexible' (from what I have seen).. Blade - Taipan - Viper. Enough said. We don't have Spitfires etc here to measure so I can't comment on those.

Viper 137kg
You should know how much each daggerboard and rudder weighs from an F18! Pre-production Vipers used these but the Viper foils (same profile as the Capricorns but different layup) are way lighter. They'll never weigh the same as the Taipan ones as they are a lot longer. But at 1.5 v's 2.2 kgs (per daggerboard Taipan v's Viper), its not a huge difference.

But I have this to say about the weight issue.
There aren't that many manufacturers who can effectively build a cat to the paltry weight of the Taipan! That boat is a real benchmark - that takes some doing. Certainly the big manufacturers can't (won't do it) so that leaves it up to the smaller custom builders. If the platform weights stabilise at a reasonable level then maybe, the big cat factories might get interested in building cats for the class. When (if) that happens, it will be a good day for all parties. More manufacturers means more interest. More interest means a bigger class. A bigger class means more competition on-the-water and between factories - that's ultimately good for the end user!

Interestingly
The Viper straddles both the F16 and the F104 almost perfectly! The 'bare' Viper suits F16 Class add a few kg's and its a perfect fit in F104 - that's pretty handy!

More interesting
It will be much more interesting if I set up the standard Blade and the Hybrid Blade and use the same test. That way I can comment directly about how we improved the deflection by using the F18 beams.

One thing for sure we are never going to have any beam issues with those beams installed on an F16! If they can take the loads of the F18 they'll have no worries with a lightweight F16.

Carbon
If weight savings is the real deal, then I can tell you that soon there'll be Carbon rudder stocks available for Taipan, A-Class and Blade with Viper ones to follow a bit later. These are under going development right now at a factory in Asia and will be released soon.

In any case, I look forward to getting the Hybrid back on the water this weekend for another shake down!

cheers

Thanks Simonp
I agree. Maybe I should have written "that's when I very quickly learnt that F16's need you to get the crew weight right back." My point was I don't think the Viper is very different in this regard, despite the talk of higher hull volume compared to other designs.

he he that's quite funny because that's exactly what I experienced!.. when I sailed the Hybrid Blade for the first time. But I think I had the mast rake a bit forward.. so changing the rake this weekend! - We'll see!

But correct me?
We've heard that the Aussie Built Blades have...
1. more freeboard in the bow and,
2. they have bigger beams?

Notably, the Blade is quite okay to sail with the leeward nose dragging through the water - doesn't really slow down that much!

cheers

Scott,

You are obviously a representative of Prosail Asia & a AHPC distributor, be very carefull when making "blanket" statements when referring to the "Blade" range of catamarans.

In future you should either refer to a blade as

1. - Home built Blade F16 (Various Locations)
2. - Vector Works Manufacturered Blade F16 (USA)
3. - Formula Catamarans built Blade F16 (AUS)

I make this statement as I personally have viewed all three with great interest & while the 3 boats have come from the same designer, they all have variables that can not be referred to in a single statement.

Personally I also struggle generally people making unsubstantiated comments about products they have not had the opportunity to survey.

On a lighter note - I am now very envious that your local club has nearly 40 F16's sailing & I would love to bring one of our boats to line up for the "Face Off"!

I've only sailed the Aussie Blades and haven't seen a VWM blade in the flesh. So I don't know about all the differences. I know the decks and beams are different. The FCA Blade has more rounded decks, and no trap tracks on the inner gunwale (lace the trap to bolts on the boat instead). The beams are a D shaped tube with a built in track, and at a guess 2/3 the size of the viper's. Under the water I think the differences are minimal.

I'll get some photos this weekend and post soon.

Maybe someone that has been to the global challenges, and seen the two boats side by side will be able to explain the differences.

You guys are certainly a sensitive bunch.

LMAO <img src="http://www.catsailor.com/forums/images/graemlins/laugh.gif" alt="" /> <img src="http://www.catsailor.com/forums/images/graemlins/laugh.gif" alt="" /> <img src="http://www.catsailor.com/forums/images/graemlins/laugh.gif" alt="" />

<img src="http://www.catsailor.com/forums/images/graemlins/blush.gif" alt="" /> <img src="http://www.catsailor.com/forums/images/graemlins/cool.gif" alt="" /> <img src="http://www.catsailor.com/forums/images/graemlins/blush.gif" alt="" /> <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" /> <img src="http://www.catsailor.com/forums/images/graemlins/cool.gif" alt="" /> <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

Second that...

Most of the compression on the mast goes down the leeward side of the mast tube, becouse the windward diamond is supporting the tube very well. Mainsheet is also supporting the tube through the roach/cloth of the main. There is not a lot of compression on the mast compared to twin wiring upwind. The only way I can see to get 8cm of dynamic movement in the spi luff is by tuning the kite on the beach with a 200Kgs gorilla jumping up and down in the trapeze at the stern, some serious flex somewhere or a mainsheet released completely.



So why did you rank the beach handling with Blade as the worst? Should it not be Taipan4.9, Vectorworks Blade, Viper?
I am part of a group building three woodie Blades just now, so this is all very interesting. A lot of what you say dont make sense to me, like the above and why you need to strengthen the hull in front of the mainbeam becouse you put a different F16 rig on the platform. Is the water more viscous becouse of the new rig?

Rolf,

Agreed there would be zero compression out of the mast......most likely it would come from bow tips flexing or stretch in the halyard. There has been endless discussion on the effect of the spin luff issues. I know you know what is right or wrong.

With regard to the hauling of boats up the boat ramps.....unless the rollers are identical, then comarisons are just hot air. <img src="http://www.catsailor.com/forums/images/graemlins/shocked.gif" alt="" />

Marcus

Errrrrr.........where did you pull that figure from.....AHPC website advertises 125kgs.....rumors are the boats are arounds the 127-129kgs.

If you are an AHPC rep, then i suggest you provide factual info rather than marketing tactics?



The viper comes second because you have to use $600 euro rollers.? <img src="http://www.catsailor.com/forums/images/graemlins/shocked.gif" alt="" />

<img src="http://www.catsailor.com/forums/images/graemlins/cool.gif" alt="" />

That is one way to do it ! <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

Good to hear your problems in this field are over.

From what you tell, it shouldn't affect any of the F16 sailing characteristics.

Best of both worlds !

Wouter

Ducati Scott,




I and several other know exactly what these weighted ! When Greg wasn't looking we placed everything on the electronic scales at the Global Challenge 2007. The same scale that were used to check all other boats for compliance. So we know exactly what the weights were and the relative differences between it and all other boats that were present there.

There have been several posts on this subject in the past, although the participants of the GC 2007 were kind enough to be a little restrictive in publizing these specs. Some of them were quite shocking and honestly we all respected Greg to come out with a prototype boat at our event and deeply felt for him when a forklift truck had run over the shipping box a few times in a row, severly damaging the hulls.

I'll give one example, The prototype Viper daggerboards were a tad over 8 kg per pair where the next set in weight (mine, AHPC Taipan daggers) were 4.2 kg per set, the sets of new Stealth and Blade boards were respectively 3.2 kg and 3.6 kg per pair. Thus the difference being almost 5 kg on a pair of daggerboards alone ! None of the boards broke at the event and we had very rough weather.

I'm totally convinced that the Viper can be 120 kg when the guys building it are paying attention.

Sadly, I learned that "can" and "will" are not always exchangable in real life.

I'm hoping for the best !

Wouter

I too am a little miffed about this statement. Considering the tight rules in the F16 class and the fact that all alu masts are identical (they are all the AHPC superwing) I wonder how a 120 kg Viper F16 can be easier to push about on the ramp then another F16 design that is close the 107 kg class minimum ?

These boats are all the same length, width, height and differ very little in ready to sail weight (13 kg = 10%). Even the freeboard is never more then 50 mm apart on an average height of 450-500 mm (= 10%) taken over the range of designs from the Taipan to the Viper.

I agree with Clayton that I would like to see independent confirmation of the ready to sail weight of the Viper; just as I had desired of the other makes in the past. So I'm looking forward to an official F16 class measurement certificate for the Viper F16 !

Didn't the new Viper at the GC 2008 in Mumbles have one of these ?

Wouter

@ Wooter

You are the veritable cataloger of boat specs. But I am wondering, if sailor weights in Singapore are "typically light" are those of NW Europe, ah, typically heavy? <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />

@ Ducati

Thanks for explanation on beam. You mention that you are looking out for "speed robbers" and that makes a good point on boat selection --

Whatever drives a buyer is what they decide is the most important aspect of any boat. For HP boats, of course, the consideration is speed and the primary issue is whatever robs the speed. Whatever it takes to trim and go faster.

"Search" forum feature is our friend. I have spent time reading:

Trouble in Paradise

F16 Future

What's the skinny on the FX One

Goes to prove, I believe, that there really are never new questions or answers... probably.

Which leads to another part of the point: One other aspect of the selection process is how boats address tweaking up and, as well, "tweaking down".

The F16 is an interesting boat in that respect. As Wouter and Ducati and the new formula 16 brochure address, it has innovations.

But, also it is solving a few "tweaking down" problems: one-up or two-up sailing, less pitch-prone bow design, lightness.

The list for me has always been:

Manageable size and weight, solo or two-up capability, average durability, mast raising that doesn't require a crane.

F16 hull durability issues I consider somewhat spooky. I note this comment on another thread from Buccaneer on bringing a boat to shore:



Practical, but implies a huge assumption. That assumption is that these boats are deep water boats. You don't worry about hull damage where there is deep water. If you are in tidal waters or where rocks and underwater features are a risk, then you may want another boat altogether.

Although, it looks like Will now has part of a compromise.