Rob Zabukovec

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About Rob Zabukovec

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    Multihulls, especially Proas

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  1. Rob Zabukovec

    ORC and sport boats

    Not only phoney, but a sucker for punishment. The forward guard still doesn't comply........
  2. Rob Zabukovec

    2017 Australian Multihull Championships

    Tony, My own VPP tells me that my 9.5 metre boat should be roughly the same speed as your Diam. But over an average 20 mile race, your Diam would beat me by over four and a half minutes on OMR. Bearing in mind that my boat has 3 bunks, full (for me and my wife) headroom, a galley, heads, what do you think the reality would be? OMR for me will never happen. But I do care for the bulk of existing OMR fleet and where OMR is heading. I have raced for over 30 years under IOR and IRC and sports boats including Melges 24s and have seen all of this happen before. And a lot more.
  3. Rob Zabukovec

    2017 Australian Multihull Championships

    That is the problem, biasing the rule with a bit more weight for accommodation doesn't work. OMR was there before. You can still have an (artificially) overweight sportsboat and do well. Make that sportsboat have a minimum headroom, at least 3 bunks, galley, heads water tanks etc and see how much extra windage vertical CG shift and pitching you get. Never mind the weight, try fitting all that into a Diam. In the MOCRA rule, a Diam would carry a 5% penalty for the lack of headroom alone. In the Texel"cabin" multihull rule, (as opposed to the "open" cat/tri rule) it looks to be around 6%.
  4. Rob Zabukovec

    2017 Australian Multihull Championships

    And for those who still want a proven multipurpose competitive offshore multi to race against the (inshore) OMR sportsboats, get an M32 cat, current record holder of the 750 mile Race to Alaska. Complete with "unproven" T rudders and curved foils (0:05 to 0:15 secs into video). The off watch crew sleep/rest on the racks in bivvy bags with a knife in hand, so that they can cut themselves out quick if the boat flips and the zip jams. You could also trapeze off the racks to make more room for the offwatch crew, especially when cruising. Nothing specific on the OMR website that I can see says you can't..... Downside is that the design is pretty old compared to the latest modified Diam type and will need an optimising upgrade to stay on top of the game. Too much windage in the bows for starters..... And if it can survive 750 miles offshore, it is obviously overbuilt for (Inshore) OMR and will need to lose some weight.
  5. Rob Zabukovec

    2017 Australian Multihull Championships

    I totally agree with your second sentence. Your third sentence is a complete contradiction..... Carrying on from my earlier comments above, I could have also said that Sports/Dayboats, due to not having to provide hull freeboard, cabins, bunks, heads, cookers and all the other paraphernalia for cruising and offshore use are abnormally light, which means they have abnormally good Displ/Length and Sail Area/Displ ratios. The former being beneficial off wind and the latter good in the lighter conditions you normally gets for inshore championship conditions.So, some words of advice to owners of older multihulls and even condos who want to try their luck against the "best" sailors, it is dead easy, all you have to do is update your boats, including, but not limited to:1) Rip out all your bunks, heads, sink, galley, cabin tops (especially aft ones) and put in an oversized ergonomic carbon cockpit for efficient crew work, lighter weight and lower CG.2) Chuck you short low displacement amas and get full length carbon high displacement ones. Reinforced to take curved foils. And make them ergonomic while you are at it, so that the whole crew can hike out hard on them.3) Chuck all your foils and replace with carbon curved centreboards and T rudders.3) Chuck your aluminium mast and go for a carbon mast, preferably ultra high modulus carbon.4) Scrape off all the antifouling and polish the hulls.5) Get new optimised sails including upwind screechers.6) Best to pay experts like VLPL, Grainger or a top sailmaker to advise and oversee the updating process.Or it might be simpler and cheaper to just to go out and buy something like a Diam and have two boats. At least you will still have one you can cruise in and go offshore with.And finally, I know of one well known racing multi who has a certificate listed as carrying 2 anchors, a try sail, a life raft, and possibly, an oversized battery and spare or specialist "legal" sails. All to get the weight up (low in a good place) and the rating down. Should it turn up to the next Australian Multihull (Inshore) National Championships, who knows and who checks that they are all on board as per measurement condition? Or do you just blame a load cell?
  6. Rob Zabukovec

    2017 Australian Multihull Championships

    You could say the same about any rule, including IRC, the most global rule, with the longest track record and where sports/day boats have been specifically excluded for good reason. But the "best" OMR sailors have and will increasingly gravitate to sports/dayboats where all the "free lunches" like T foil rudders, curved foils, canting rigs, carbon spars etc work best. And where (movable) crew weight for trim is a much larger proportion of the overall sailing displacement. And the reduced windage and lower CG with less pitching because they don't provide any real headroom or any significant internal volume. And they are more manoeuvrable for short tactical racing. And none of them stay in the water so don't need to be antifouled. And are more recent design with no age allowance for old designs. And...... It is a trend which will make the bulk of the existing OMR fleet, the multi purpose accommodation carriers, obsolete. Which will suit the "best" sailors in their sports boats no doubt, but is it good for multihull racing overall? How many "best" sailors would race OMR in a brand new multipurpose accommodation carrying design with those inherent handicaps? Now there is a challenge for you...... Never mind the cost. Good Luck with it.
  7. Rob Zabukovec

    2017 Australian Multihull Championships

    ^^^^ BINGO BushSailor lives in a fantasy world. You just have to compare OMR and MOCRA preambles and rating rules to see that. OMR can't even get ratings right. How many curved foil boats are there currently racing OMR? At least 3 at a guess. How many are there on the current OMR ratings spreadsheet. Only one, the G32? And how about the Ad Hoc cowboy nonesense of the weighting fiasco at Airlie last year? Most of us can live without that sophistication. If it is a development rule, why penalise/rate curved and canted boards, and give a free lunch to other things like T foil rudders and, I forgot, canting rigs? Why penalise/rate anything? OMR will become a type forming rule. No cabins, no bunks, T foil rudders, canting rigs, etc. It is not about penalising, just applying an appropriate rating to anything which should/does make a performance difference. They can all be reviewed annually. MOCRA does formally and also has a formal appeals procedure. Does OMR?
  8. Rob Zabukovec

    2017 Australian Multihull Championships

    If those controlling OMR want it to be a no limits development rule (with or without mizzen masts) and with no allowance for age or alternative uses and just be expensive carbon dayboat rockets on short race courses so be it. If as I suspect most multihull owners in Australia can't/don't want to fit this category, maybe it is time to have a separate division using something like the MOCRA system, which has a very clear intent and structure, and is used in the UK even for the Fastnet Race and which does give age allowances and requires headroom, a minimum of 3 bunks etc, etc. It already rates T Foil rudders and lifting foils, unlike OMR, but not mizzens, AFAICT. I see little point in just setting up a "cruising" division of OMR because eventually all the obsolete Diam mk1's and the like will end up there when they are sufficiently outclassed by Diam mk'X or whatever, repeating the problem all over again. Nothing against the Diam..... Lovely boat.
  9. Rob Zabukovec

    2017 Australian Multihull Championships

    1) The top/best/most competitive crews aren't naive. They will always gravitate to the types of boat and modifications which are perceived to get the best rating benefit. 2) "Sports" boats designed for day sailing and short races will always beat boats designed to be for multipurpose/offshore use. IRC recognised that decades ago. 3) The latest designs should always beat (significantly) older boats. That is evolution. IRC recognised that decades ago. 4) T foil rudders, curved foils, lifting foils are still all "free lunches"? Even the extra weight involved is a rating benefit. How does OMR deal with the last three points? The first point also usually gives a clue about what might need to be addressed.
  10. Rob Zabukovec

    2017 Australian Multihull Championships

    Lovely boats, but if "beach" tris have abnormally good ratings in O(ffshore)MR that would suggest that there is an anomaly in the rating system.....
  11. Rob Zabukovec

    beach cats in the ocean?

    Pete Goss is also a brilliant inspirational/motivational speaker. Early in his "career" he gave an after dinner speech at a charity regatta I was involved with. Even the kitchen staff came out to listen and you could hear a pin drop in the middle of a hall full of hundreds of well oiled sailors and their guests. As for watch systems, I have done a fair amount of single handing and offshore racing and I have no doubt that the safest and most relaxing way to go is with a 3 hour 3 watch system, on, standby and off. Which guarantees 3 hours off in a bunk and usually meant 6 hours off. Fatalities on R2AK, sadly, will eventually happen one day.... They nearly had 3 in the inaugural race. One guy could have died twice. R2AK is as tough as it gets. Until/if Randy Miller gets around to organising the 1000 mile version in Patagonia....... Not in the R2AK league, but the Texel race has been around for a long time:
  12. Rob Zabukovec


    More likely to be a French one off. What sort of rig did it have?
  13. If you had all 3 crew at 100 kilos each sitting on the canted rig T35 windward aka, you get to the CE/CG neutral point at about 12 degrees of heel. Heel a bit more, and you are in ama lift territory, but the vertical lift component is so small as to be meaningless and at 15 degrees is gone. The real advantage is that if the mast was conventionally heeling at 15 degrees, the rig produces a downforce, making the ama dynamically heavier than it would be otherwise, with more sink and resistance/drag, even though it is a righting moment in itself and the overall heeling moment is significantly less than vertical. So if you fly a canted rig T35 at 12-15 degrees heel, you have no main hull resistance/drag, no additional dynamic ama sink resistance/drag and negligible/zero ama uplift.
  14. If you adjust the T35 cross section above to get a 15 degree canted mast vertical, you have to fly the main hull at least 300 mm above the water. Windward ama would be roughly 1600 above water and the CE would be over 700 mm higher. So pretty much like the F32 photo.
  15. I can't disagree with you. Extra heeling moment in itself isn't slow. In lighter conditions, it might be an advantage. If you have significant dihedral, maybe your effective cant is only (say) 10 degrees. CE will move to leeward more than CG when heeling. As soon as a vertical mast starts heeling, it loses heeling moment/power. The exception being in extremely light conditions when the benefit to sail set can be better than power lost. It could be extra RM from the canted mast is more than the extra HM because your CG is close enough to your canted CE. Do you stack the weather ama with crew? What is it like if the curved boards are fully up and play no possible part in lift? There are also other benefits to canting masts, including reduced tip vortices because more air is directed down which increases again if you have an effective base endplate.