Thanks, Don, this seems to confirm my findings on our 35-2 - although we don't race, we often are trying to make some miles on long downwind runs. While I haven't done too much testing since getting real instruments, it seems that I can sail deeper downwind as the wind builds and still get a good VMG. Of course, I am sailing with only a genoa and no pole, so keeping the sail full is often the limiting factor for downwind angle, but at 20kt + I can often go very deep if the seas are fairly calm. If I expect 20kt+, I will also not bother with the main, as I can get near hull speed with just the genoa, and we certainly won't be surfing much with a tonne or two of cruising gear on board...
-- Shawn Wright shawngwri...@gmail.com S/V Callisto, 1974 C&C 35 https://www.facebook.com/SVCallisto On Tue, Oct 12, 2021 at 8:15 AM Don Kern via CnC-List <cnc-list@cnc-list.com> wrote: > Jeff, > > Let me assume that your boat is similar in performance to my 35 Mk2 and > the wind / currents are similar to what we have in New England. That said > I hardly ever worry about sailing to the laylines. First, hardly ever is > the leeward mark set dead downwind and there should be a preferred side of > the course to sail which may be modified due to tidal currents. You > figure that out before you start and set the pole and guy/sheet > appropriately. Then you watch to see what lead class of boats due upon > rounding windward mark to confirm the downwide course settings, if you are > not in he fist class to start. When you round that mark your fist > imperative is to clear your wind either reaching , bearing off or jibing. > Next, if you are in the lead, is cover your most threatening competitors, > if not in the lead keeping your wind clear and if wind is light to moderate > sail to the favorable current (max or min depending on current direction). > Because of my boat's older design I sail deeper downwind for max VMG then > the newer boats which sail closer to a reach (wider down wind angles). > Strategy and tactics usually will keep me away from the layline which limit > my options. If I am the lead boat I try set up so rounding is just get the > chute down and harden up without sailing into the lee of the competitors. > Normally because I have sailed deeper and have avoided the laylines, the > newer competitors are approaching from wider outside angle and my tactic is > to protect from being overlapped to the inside as I get to the 3 boat > circle. > > From the above you can see I hardly ever sail off into the wild blue > yonders of the laylines, Strategy and then tactics predominate my down wind > sailing. > > Don Ken > Fireball, C&C35 Mk2 > Bristol, RI > > > > On 10/12/2021 8:33 AM, Jeff Nelson via CnC-List wrote: > > I'm really not following your math here. > Perhaps some clarification: > TWA = True Wind Angle (I think you refer to that as TWD True Wind > Direction below) ie 270? > Course = 230 deg > Tacking Angle = 80 deg > New Course = 310 deg > Course to Leeward Mark = ? > > This statement is confusing to me: > "So, when the windward mark is at a bearing of 80* I'm on the leeward > layline" > In this example we are going to the Leeward Mark (downwind mark). I > believe you are heading to the port layline, > The windward mark would be the one you previously rounded. > > With all of the above...It seems like an aweful lot of math to do in the > heat of the battle. Since you likely know the > course to the mark, and you've already determined your gybing range (80 > deg). Isn't it easier to add or subtract 80 to > your course to see if it matches the bearing to the mark? This can be > achieved from your chart plotter BTW (Bearing to > waypoint) or via handheld compass if you can see the mark. Maybe that's > what the math below does, if I plugged in > the right numbers, but the closest I could get was 180 - course (230) = > 310 but if I multiply that by 2 I get a course of > 260 which wouldn't be your layline, as you need a course of 310. Also, if > I use any of those course numbers, they will > remain constant, whereas the bearing to the mark will constantly change as > you get further from the rhumbline (dead down wind). > > Cheers, > Jeff Nelson > Muir Caileag > C&C30 - 549 > Armdale Yacht Club > > On 2021-10-11 10:07 p.m., Bob Mann via CnC-List wrote: > > My geometry for calculating leeward layline: > If my ideal heading for the current conditions is 230* and TWD is 270*, > that means my stern has to swing 40* to become dead downwind, and another > 40* to get to the reciprocal course after the jibe. In a perfect scenario, > this means an 80* swing. So, when the windward mark is at a bearing of 80* > I'm on the leeward layline. Bearing to the mark can thus be calculated as > 2 x (180-TWA). > > Bob > > On 10/08/2021 11:15 AM Bob Mann <sailrm...@comcast.net> > <sailrm...@comcast.net> wrote: > > > I still need to review the geometry, but I believe that when the bearing > to the mark is equal to 180-TWA, one has reached the downwind layline. I > also found that when the masthead is pointing at the mark, that also > indicates the layline has been reached. > > Bob > > On 10/06/2021 11:17 AM Jeff Nelson via CnC-List <cnc-list@cnc-list.com> > <cnc-list@cnc-list.com> wrote: > > > Hmmm...Interesting question. > > So, Ed's answer was pretty good, I'll add a few thoughts here: > > AW isn't an ideal guide, True wind is what is needed so that you can keep > the angle to true wind to be constant on > either Gybe, assuming you know what the best angle is. > If you can find polar's for your boat, they will give you an idea of > ideal. > As Ed mentioned, VMG is your friend in determining what the best angle is > (especially if no polars are available). > You can experiment in different wind speeds to find a reasonably good > angle for windspeed and VMG. > > Here's a good article to get you thinking: > http://www.oceansail.co.uk/Articles/VMGArticle.php > > Hope this helps. > Jeff Nelson > Muir Caileag > C&C 30 549 > Armdale Yacht Club > > On 2021-10-06 12:02 p.m., Bob Mann via CnC-List wrote: > > I'm fairly new to flying a spinnaker. I did it last weekend in a race and > I believe I overstood the mark as we were sailing 110 AW before the gybe > and 85 AW heading directly to the mark. > > How does one determine when to gybe? > > Bob > > Thanks to all of the subscribers that contributed to the list to help with > the costs involved. If you want to show your support to the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - Stu > > > > > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient> > Virus-free. > www.avast.com > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient> > Thanks to all of the subscribers that contributed to the list to help with > the costs involved. If you want to show your support to the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - > Stu > > > Thanks to all of the subscribers that contributed to the list to help with > the costs involved. If you want to show your support to the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - Stu > > > > Thanks to all of the subscribers that contributed to the list to help with > the costs involved. If you want to show your support to the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - Stu > > > Thanks to all of the subscribers that contributed to the list to help with > the costs involved. If you want to show your support to the list - use > PayPal to send contribution -- https://www.paypal.me/stumurray Thanks > - Stu
Thanks to all of the subscribers that contributed to the list to help with the costs involved. If you want to show your support to the list - use PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - Stu
