I agree with Timbo on this one. If you want to go faster put your jib on. There is no class minimum crew weight so i wouldn't have a problem racing a one up boat with a jib.

Ah but very true.

As we are in the " F16 " forum and I did ask the question.

5m x 2.3m wide, quite a bouyant hull form not unlike the latest Nacra F16 which seems to skid across the surface with its bow ( and hence shorter water line length )well out of the water with only 1 on board, A class style rig 8.5m high ( without limits on the Leech length on the main ), 13 - 14 sqm main and 2.5 sqm blade jib. 16sqm spinny weighing in at 100 kilos. 6 degree angled boards.

With a change of the rig and sails it could be used for adult dual handers, leave it as it is for light weight dad and nipper. Sorry but the mast stiffness and aspect ratio of the sloop sails are just not suited to the lighter RM of the single hander.

Why the jib, I think we are all pretty much in agreement that the jib just makes setting the main just so much easier for the non expert sailor that with a jib on 75% of sailors will get to 75% of the efficency of the mainsail pretty quickly. Yes a Uni would be faster but only that top 25% of sailors will get the best out of them.If we don't run a jib then we may as well just buy a Shadow X http://www.shadowsailing.org.uk/the_boat_x.htm very very fast boat if you are around the 75 kilos with a strong class association and organised races, actually I'm surprised that 1 or 2 haven't been entered into F16 events already particularly if the wind looks like getting up. The shadow was originally only 90 kgs, not sure how fitting a pole and slightly larger sail takes them up over 100kgs, mmmmmm

SCHRS handicapping puts unreal expectations on the jib, a boat like the above would handicap out faster than a Tornado, simply unrealistic and thus one would have to go almost directly to an A Class rig with 17.5 sqm spinny ( which I think would be too large for the average single hander )

A dedicated 16 footer, simply chop off the rear of a DNA and move the beams and boards slightly foward, fit a 16 m spinny in a dedicated Y beam snuffer ( to keep the wind drag down ), A rig and C boards, about 90 kgs.

After 5 years of on the water testing on the Stealth and now Bitsa, thats where I have got to.

Everybody keeps talking about righting moment being an issue. That sloops go faster in stronger winds because the uni is on the wire too soon... It seems to me that if that is the issue, then the obvious answer is to lower the center of effort on the sail, for both configurations, which means a shorter mast, and possibly a smaller main.

The above is *not* meant as my entry into the fray. I don't know enough to add to the discussion in that way, but I do want to ask a question...

From the comments here, you would think that this is some kind of grand experiment, that there has never been a class that allowed both 1-up and 2-up sailing. Yet, AFAIK, there are several classes in Australia that do just that (the Taipan, and Cobra come to mind,) aren't there? How do they handle it?

A smaller main has been mentioned by several knowledgable people who have been around from the beginning.

I guess it's a "manhood" thing, no one wants a smaller one.

A shorter mast sort of complicates and makes the issues of RM worse off. By going to a shorter mast we lower the aspect ratio of the sail, making it less able to be depowered ( remember most modern sails and mast combinations are becoming more bendy in the roach and thus with powerful downhauls we can control the amount of power generation the top of the sail can produce, the A's are almost self governing now depending on batten strength etc. )and more " draggy " in higher winds.

There are also all sorts of issues with a lower AR sail also moving the centre of effort too far to the back of the boat causing tacking problems and all sorts of issues with the rudders and dagger board positions.

If anything we need to go to a higher AR sail where the uni can control the power of the sail better. One of the easiest ways would be to simply remove the lower sail limits out of the class rules, that way the sail could be made to almost come down to the deck, after all as an Uni you don't have to worry about a crew getting underneath the boom. Have a look at some of the ORMA Tris where the boom is mounted not on a tradional mast mounted gooseneck but on the deck behind the mast step.

Interesting about the Tiapan and Cobra having duals, but be aware that they are relatively old hull and sail shapes, we have moved on a bit in design and knowledge.

I agree on the topic of higer aspect mainsails being faster and easier to control than the same area in a lower aspect mainsail. Even across the windranges this holds true in my opinion.
Sails going all the way down to the trampoline is not a good idea in my opinion. The benefit is very minor and it makes it harder to get around on the boat (forget end-plate effect and factor in the turbulence + reduced airspeed down there).

I dont know the current status, but are Cobras and Taipans now sailing with a spi downwind in class competitions? They did not earlier and this is another factor to consider when comparing.

Agree having sail area down low is not ideal, but we have a problem of low aspect ratio sail area creating boat handling and design problems as a solo, so putting 1 - 1.5sqm down low ( think more windsurfer sail shape )generates a bit of power and keeps everyone happy that they still have 15sqm of sail on a 8.5 class legal mast with a higher aspect ratio not unsimilar to the A Class.

I think you'll find many uni sailors in agreement that the main is what finally puts the boat over, even down wind.

Speaking for myself, when a hard puff hits under spin I naturally drive down but hold the spinnaker for as long as possible. That can be difficult as the sterns start to lift. As a last resort, once it's clear the boat won't recover I dump the spin and make a stab at releasing the main. When I'm successful, the boat recovers nicely then it's just a matter of reversing the sheeting order and off you go. The total time is rarely more than 3-5 seconds.

The point is: that flat head sail, high up is the culprit. Imo, uni sailors would be better with something more like a pin head.

With all these ideas floating around.. We should actually build some of them and test them

The Tornado class allowed this kind of testing in class regattas as long as the mainsail had a big XX and the results was not valid for the awards or ranking.

My first main was a Redhead, built in Australia maybe. It was sort of a pin head. Maybe I'll take it to the sail maker and see if it's salvageable.

If he can't add more top to it, you could have him cut it down a little, off the foot, and use it for very high winds.

I'm not following you. The Redheads are the sails I started with. Rather than send them to the sail maker for repair I bought a new set of Goodalls that were fuller at the top.

my 2 cents. I can't make my boat go 2-up. Maybe that is because I always sail it solo so I have a different "vibe." In the few CRAM races I did this year, I did well solo. I did better solo than with crew on one of the days. In light winds I think uni wins out, but that is light air.

I was thinking you could use the Redhead main for a 'high wind' main, ie. get it cut down, flatter, maybe take some off the leach, shorten the foot a little too.

OR...if you'd rather make it bigger, have them add some to the square top, to make it more like your newer sail.

Interesting about releasing the main sheet, I always have been told the minute you release the main in an impending nose dive caused by the spinnaker powering up too much, it presents the top of the main more to the wind now coming from the rear, which simply makes matters worse as well as possibly putting even further stress on the mast which is now unsupported by the main sheet.

The really good sailors seem to never get into the position of the spinny over powering the boat and seem to be able to just go faster and faster all whilst on one hull. I remember John Pearce at a very windy second F16 champs I attended saying its better to get the windward hull even higher off the water in big breeze as it presents the side of the hull to the water and therefore has a better chance of not diving, as he won the event I have to probably believe him.

Part of a message I just send Rolf in a PM conversation:

I did quite a bit of work a couple of years ago on a design for a dedicated single handed F16 and couldn't come up with something within the rules that I felt would be competitive enough to justify committing the money to build. As you know there are a couple of issues. The not enough hands thing is the big one as righting moment can be worked around (A classes have less righting moment than an F16 but are faster around the course). Extra hands makes the sloop rigged boats not only faster at the marks but all the way around the course, upwind you can be playing main and Cunningham not one then the other, downwind you can play main and kite not just kite and with two hands the crew can play the kite, not just pull it on and hold it like you end up doing when cat rigged. This gives a big advantage, for example without a kite sloop rigged Taipans and 5% faster around a course than cat rigged.

I believe this issue was originally masked in the F16 class because of the nature of the early adopters, which could be loosely grouped into two brackets; the cat rigged boats were skilled/experienced sailors looking for the extra challenge/ thrill of using a kite and the sloop rigged boats were couples and/or parent child teams looking for a way to introduce a partner to sailing with the ability to go still go sailing on days they weren't interested. Now that skilled teams are becoming more common on the sloop boats the real status quo has become obvious.

Fixing the issue is hard, particularly if people want to maintain the ability to switch between modes on the one platform as any systems implemented to make sailing a cat rigged boat easier if successful will also be applied to the sloops. For example I played with the idea of having a furling kite. This could be easily hoisted on a 3:1 halyard from trapeze while approaching the top mark and as you turn the corner you just have to sheet on, reverse applies at the bottom mark, furl as you approach then drop once you turn the corner.

With this in mind we need to find ways to make the cat rigged boats 5% faster in ways that can't be immediately copied on sloop boats, which requires a relaxation of some rules for Cat rigged boats. At this stage it would be worth getting Mark S involved in the conversation as the SCHRS rating system can be used to calculated the returns on potential changes.

Some changes that could be considered:
1. Removing the tip weight limit on masts for Cat rigged boats which would allow people to use A class masts.
2. Removing 1/2 girth limit on kites
3. Dropping the minimum weight 10kg

Be wary of the SCHRS handicap in regards to light weight boats and single handers, the calculator does give some strange results, one only has to look at the present equal rating of the Uni and Sloop, on the water results would indicate otherwise.

If you get the chance try putting into the calculator the Uni's specs and then add a blade 2.5 sqm jib, gosh we would be the same speed around the course as a Tornado. Mmmmm

Wayne,

I think the issue with the Uni V's Sloop rating is based upon the theoretical performance of the two boats (like a calculated rating should be). The problem is that in the real world unless being raced by octipii you can't sail a cat rigged boat to the same level of its potential as a sloop rigged boat. The question is how close can you get? The VYC ratings in Australia are based upon decades of emperical data and suggest the cat rigged Taipan is 4% slower than the sloop rigged boats, I'm guessing with kites this would blow out a bit to 5 or 6%.

Now, if the calculationed ratings show (and I don't know if they do) that a cat rigged boat should be the same speed as a sloop then that means a crew of two can get about 5% more performance out of a boat and to get level racing you'll need to make a cat rigged boat theoretically 5% faster than the sloop, not the same. This way once crew skills are applied the two boats will in fact be equal. SCHRS or any other calculated rating (Texel) if at all accurate can be used to weigh up the options and see what cat exclusive rule change would produce that 5%.

Next question for those in the know (and I suspect I know the answer from another conversation) does the SCHRS equation really rate cat and sloop at the same speed or are they rated that way because the F16 class has asked them to be?

Up until 2011 the Uni was actually rated faster than the sloop under SCHRS. The SCHRS technical committee spent appreciable time investigating what many felt an onerous handicap for the single handers and in the 2012 review ( http://www.schrs.com/img/pdf/SCHRS_Improvements_2012_updated_29_4_2012.pdf )set about changing some of the parameters to at least equalise the two boats. To change the handicap further would have meant appreciable change and the technical committee felt that bringing the two boats into line was for the moment as far they wanted to go. Changing further also had other ramifications on other classes as well. Read the report and you will get the picture.

5% is probably about right around the cans, but how can you get those sort of gains, yes A Class masts and sails will help, but we have to get more drive down lower so that RM isn't the major factor. Allowing the use of a small jib is probably the only way that can be done and no, in my opinion widening the boat, will only create further problems.

At the end of the day, if we as a class acknowledge we have a problem, we can all work together and if as I suspect we reach the conclusion that no, we can never equalise the boats, then we simply adapt our class stratergies to suit.

Also I think that the differences in speed are dependant on wind strength. At lighter winds the Uni might even have an advantage and in heavier winds its a larger disadvantage. Where is the cross over point?

Trying to come up with one rating number that covers all the wind ranges might not be possible. What do you guys think?