Heavy-Air Boatspeed Notes- 2010 Midwinters
Sunday, February 28, 2010
Below are a few of the notes from 8931, particularly relating to the heavy air we experienced on days 1 and 2 of the midwinters. Notes were compiled from daily de-briefs mainly with Mike Holt (2009 Worlds runner-up) and other top teams in attendance at the regatta.
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Conditions: 15-30kts. Seastate ranging from steep 4-6 foot swell (S/SW breeze Day 1) to flat 1-2 foot waves (N/NE breeze Day 2)
Upwind
Rig: Overall theme from the weekend was that everyone should be raking much more, much more quickly up the breeze range. MH is able to rake back to 24’7” on his boat, and felt that at our weight (340), we should reach this max rake setting in as little as 18kts. The transition from 25’8” to max rake thus takes place over a relatively narrow total wind range from 10-18kts for lighter teams. Many boats, including ours (2007 Jess Rondar), may need to move their mast base forward 1 hole from the standard max aft setting in order to achieve sufficient rake. This allows the mast to be rammed sufficiently at these extreme rake settings without hitting the back of the gate.
Basic Controls: MH noted that many teams were sailing with too little Cunningham, which he identified as being a major adjustment to flatten the front of the main and twist open the top leech in breezy conditions. In heavy breeze, he wails on this control (8:1 control line!) and leaves it there. It is critical to do the same for outhaul and flattening reef as soon as the boat is significantly overpowered.
As soon as max rake is reached, the skipper needs to begin to dump vang until he/she is again able to keep the main sheeted inside the transom corner. It is important to match twisted settings for the main by opening the slot- MH mentioned that he moves jib leads (outhauler) to within 4” of the gunwhale (!) and sheets the jib hard in this breeze. Having a nice open slot facilitates a wider groove and lets the skipper drive the boat down for speed (see below).
Foils: 8931 sailed the regatta with a new Waterat 480, and felt this was a significant improvement from the much larger Jess board (~520). Aggressive raising of the board/ vertical pin was recommended to match CoE from increased rake and keep helm neutral and prevent the boat from “tripping” as speed increases during upwind planning. MH felt that max up for the waterat board was ~ 3.5” of up and ~2.5” of vertical, though many felt that you could be even more aggressive if you were lighter. As with rake, I feel that many teams could be much more aggressive in using this control.
Technique/ Other: One of the great revelations from the 2009 worlds was that the top two boats sailed over a mile greater distance over the worlds course vs. the fleet average. MH felt this was an “80/20” statistic; i.e. 20% of this distance was upwind, vs. the remainder being downwind. The takeaway is that the boat needs to be sailed flat, on its feet, and slightly lower but at max speed/power for greatest VMG. MH explains his upwind technique in big breeze as constantly “fighting the main” to drive the boat down with the jib for power, going absolutely full-speed at all times, and only sheeting the main back in when this was achieved. Any time that the boat is not flat-out planning means that you are making worse VMG in these conditions.
Downwind
Technique: MH explained that the top west coast teams have brought their learnings from sailing other high performance boats such as 18footers and I-14s to downwind sailing in the 505. Following the greater distance/ greater speed approach to maximizing VMG, the preferred mode in full-power wire running (over 12kts) is focused on maximizing speed/power rather than sailing the boat as low as possible on the plane. Crews should be all the way back in the boat, with the skipper within 1 ft of the transom, fully hiked, and the crew just forward of that and all the way down on the wire. The boat needs to be sailed as high as possible for full speed, with vang progressively eased (power comes from the kite) and main sheeted inboard for minimum drag.
It is important to note that this technique brings another transition point into downwind sailing after the initial transition from sit- to wire-running. Trying to move to the “wild thing” when the trade-off between reaching full power vs. sailing more distance is still high (9-12+kts) does not result in optimum VMG. Teams need to have experience to know where this transition point is for their given weight/ setup. 8931 found this to be particularly true in the marginal wire-running conditions experienced on day 3 of the regatta, when many teams fresh off the debrief tried this technique unsuccessfully.
In general, this “wild thing” approach results in a significant change to technique for many of us, and one that we will ultimately need significant practice to master. Having the experience to know when to use this technique, and the confidence to make the dial-up to the max power/ speed mode before apparent wind moves forward (and boat can be sailed lower again) in a regatta situation requires practice. See also the excellent article by JJ Isler “Doing the Wild Thing” from Sailing World in 2001 for more info on this approach.
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Of course, the above is only a small snapshot of the types of things to be learned from sailing against the best teams at regattas like the Midwinters. Ultimately, the key takeaway from the weekend is that everyone needs to make the effort to attend as many events like this as they can in order to progress up the never-ending learning curve offered by the 505!
