• Announcements

    • Zapata

      Abbreviated rules   07/28/2017

      Underdawg did an excellent job of explaining the rules.  Here's the simplified version: Don't insinuate Pedo.  Warning and or timeout for a first offense.  PermaFlick for any subsequent offenses Don't out members.  See above for penalties.  Caveat:  if you have ever used your own real name or personal information here on the forums since, like, ever - it doesn't count and you are fair game. If you see spam posts, report it to the mods.  We do not hang out in every thread 24/7 If you see any of the above, report it to the mods by hitting the Report button in the offending post.   We do not take action for foul language, off-subject content, or abusive behavior unless it escalates to persistent stalking.  There may be times that we might warn someone or flick someone for something particularly egregious.  There is no standard, we will know it when we see it.  If you continually report things that do not fall into rules #1 or 2 above, you may very well get a timeout yourself for annoying the Mods with repeated whining.  Use your best judgement. Warnings, timeouts, suspensions and flicks are arbitrary and capricious.  Deal with it.  Welcome to anarchy.   If you are a newbie, there are unwritten rules to adhere to.  They will be explained to you soon enough.  

Doug Halsey

  • Content count

  • Joined

  • Last visited

About Doug Halsey

  • Rank

Recent Profile Visitors

1,676 profile views
  1. Do you collect any data from your tests? Speed, at least, is easy to get since there are now small, light GPS units available. Getting forces might be more difficult.
  2. That's really not very good advice, BobBill. Beauty is in the eye of the beholder & I'm sure there must be some who think this Snipe's sails "look good".
  3. What assumptions did you make about the velocity gradient in the Earth's boundary layer. In other words, what was the difference in true wind speed & over what distance?
  4. What's a Cb?
  5. Mach2.3 Vertical is ~41 1/2", measured the same way. The older Mach2 vertical is ~2" shorter, I believe.
  6. I find it pretty strange that you're using the past tense & referring to Moths as "ancient foilers." The class is doing just fine in many parts of the world, and the boats & foils continue to evolve. Nevertheless, I'm curious about Gacking too. I know it has been done in the Moths, but I wonder how common it ever was & whether its use has diminished as the best sailor's ability to do foiling tacks has improved. It would be pretty incredible to see one of the AC teams pull it off though!
  7. The SpeedPuck (like the other Velocitek products) stores a file that can be downloaded to a computer & analyzed in software like GPS Action Replay to display the boat's performance. If Tom would make at least one of the Astus's files public, that would help a lot in evaluating his speed claims.
  8. When I tried to get insurance from BoatUS for my Moth (3 years ago) , they told me they wouldn't insure any boats with hydrofoils. Try Gowrie Group.
  9. Sorry about that! I know the 14's are great boats & I'm glad to be wrong in this case.
  10. I don't think you'll come across many I14's in San Diego, but we've got an active & growing bunch of Moths at Mission Bay YC. Currently ~8 Mach2's & several older BladeRiders. 6 mph would be a very light-air day; more typically around 10mph or more in the afternoons. Enough for >20knot boatspeeds most days. Lots of fun! And rotating masts & other innovations are definitely allowed.
  11. You don't have to consider cant angles & leeway to find examples where having a slight V can be advantageous. It's an established fact (backed by both experiments & numerical calculations) that the induced-drag efficiency factor improves as the angle of V increases. At higher speeds, the increased wetted area & possibly sooner tendency to cavitate make the V foils have more drag. But at lower speeds, the induced drag becomes more dominant, often resulting in smaller total drag. So, it's not really surprising that the light-air foils might have more of a V shape.
  12. From the Racecourse description: "Please note: Racecourse orientation and length may vary based on wind direction & strength." So you can bet we'll see some shorter courses in lighter winds. My question is whether there is any minimum length for the course?
  13. And might some of them already be prepared to do that?
  14. Since the helmsmen can control the foil incidence, shouldn't they be able to help avoid this situation in the future by learning to reduce the AOA whenever they round up?
  15. I'm not sure exactly what the research shows, but you only mention generating more lift. So, what about conditions where the boat is fully powered up & they need to trim to minimize drag?