Wednesday, August 27, 2014

Race: Hospice regatta

This was a two day event in Oceanside with five other boats in our class. Day one was three WL races and day two a random leg race.

I went in with some expectation to be mid fleet but the first day we were missing a person in pit and a new person on board and the other boats ahead of us were all on form. Our results were 5/6, 5/6, 3/6.

The next day we went in with an extra person so had pit properly covered. Our sailing was a lot better but it was difficult to tell how we were were doing as one of the slowest boats in our class. When we got the results we were once again 5/6. Damn... especially when the silver lining though is we were 49 seconds off first place on corrected time after an hour and a half on the water.

Looking at the track we lost this race on two decisions. Firstly at the leeward mark where we wiggled deep to drop the chute and lost position to a boat in a different class, taking a slow wide rounding. Secondly I didn't commit properly to the wind going left, and sailed up the right of the course not the left. The wind then shifted left. We should have been on the left of the course.

Our starts were solid, winning two and being close on the others. Our tacks great and boat-speed felt pretty good. We're in the fight now.

Technique: This week we practiced a "stretch and blow". This involves setting your upwind sails, sheeting them in, pulling the spinnaker across the leeward side of the boat and blowing the halyard. Advantage is that you can smoothly transition to the upwind leg from a reach.

I was bow for our practice and while it wasn't quite windy enough (the wind is meant to cushion the sail above the water) and the spinnaker did get soaking it also came into the boat super easily.

That would get us halfway up the board on the RLC, then playing the shift correctly probably would have placed us near the top..... next time! Err, next time there will be something else.

Gear: Wind Transducer Woes (Update)

Couple of days later I was back at the boat during the morning calm and saddened to see other boats wind paddlewheels all start spinning before Kraken's, though it did eventually spin.

So I took another trip up the mast, this time with a soapy water sprayer. Lot's of soapy water spraying and hosing off later and the instruments were reading 20 - 40% more wind.

And now it starts spinning at roughly the same time as the other boats...

As I practice climbing the mast now things are getting faster and the time for this operation was about 30 minutes of time climbing or working at the top. However coming down takes as long as going up, and it seems like gravity should lend a hand, so I'm going to start practicing self belaying, from a nice low level to begin with!

Thursday, August 7, 2014

Software: NRace polar data issue (resolved)

This might trip others up so I thought I'd post it....

I haven't had much luck getting the farr design polar data into the Nexus race software.

Eventually I realised that the farr data for some of the downwind legs has different angles in the same column and this prevents the Nexus software from being able to deal with it.

I tried the minimal massage to keep some of the data (manual interpolating to fill in a bit, and deleting one of the columns) and it can now quantify TBS correctly. Still haven't had much luck driving the steer pilot though, that's next on my list of things to try and conquer.

Software: NMEAConnection v0.9

While away I got a chance to work on NMEAConnection. New features include:
- Finds tack and gybe points
- Generates data on these points - angle tacked, leeway, loss in boat lengths
- Has a spreadsheet
- Can draw histograms of data over sections of track
- Has a snazzy map courtesy or gmap.net
- Has a dialog box to connect to the boat
- Has a text log to help operate it outside the debugger
- Remembers core settings

On the horizon is the ability to enter meta data and a transition away from the original clunky window to something a bit sleeker. I've discovered its pretty easy to integrate C++ and managed C# so I can use winforms for the windows and integrate off the shelf applications like gmap.net, a big step forwards.





Gear: Wind Transducer Woes

Heading out on Monday to finally calibrate the wind transducer and log I was presented with a still propeller and system that told me there was no wind transducer.

Sinking feeling. Even more so when I started reading into the system and found I have the more expensive Nexus nRace model that would set me back a thousand dollars to replace.

Oh well, we calibrated the log then had a nice sail double handed. Upwind and down with a sprinkling of dolphins riding the bow and cavorting in deep blue waters. At no point did the prop consider moving.

On my return I started looking into it. Part of me wondered if an electrical fault could stop the prop like that, or if an electrical strike might have damaged it.

Looking at the server two LED lights were on under the wind connections and voltages were all pretty much zero, according to the manual this indicates a connection issue.

Climbing the mast I pushed the propeller around with a boat pole (it's a bit too high for me to safely get to with my climbing setup) but it didn't want too turn. I then pulled up the hose and sprayed it with water. Just as I was about to give up and look into removing the unit from the mast top for further maintenance it started turning and a minute of spray later was running freely.

Returning to a more sensible level I turned on the instruments with some trepidation and to my relief once again have readings!

Would probably be good for garmin / Nexus to update their manual to say the LED's and a stuck propeller could just mean go clean stuff.




The two lower lights were stuck on.

Thursday, July 17, 2014

Video:Other people having fun!

Not sailing Kraken this month, leaves me watching you tubes of others having fun.

This video was on Sailing anarchy and caught my eye, not sure I'd want to do this for 5 days but a few hours here and there would be awesome!

 

Saturday, June 28, 2014

Technique: Tacking

Tacking, on Kraken.

We have better tacking days and worse. In general they are getting better and better. We've tried a few ways of doing this but what follows seems to be the procedure that's working.

Tacking is a teamsport, and getting it right can make all the difference in upcoming crosses with our competitors.


  • Prep
    • As soon as we've tacked we get ready to tack again, the lazy sheet on the winch with no slack to the sail, the working sheet belayed ready to run free.
    • Ideally the helm gives some warning - "Tacking in five boat lengths", though this is not always posible
    • Helm: call "ready to tack". Everyone responds "Ready" of course... if not clearly call "NOT ready and give a time estimate, "NOT ready, need 30 seconds". Timing of tacks is normally critical happening either in response to the wind, or a tactical decision based on the fleet positions
    • Main: Secures the lazy traveller to prevent the main running across the boat
    • Trimmers: Makes sure enough wraps are on the new winch with the handle in place
    • Trimmers: Make sure the new jib lead is in the power position (#7 with our secondary #1 sail, #5 with our 3Di #1).
    • Helm: call "Helms a lee"
  • Tacking
    • Main: Release the backstay
    • Main: as the boat starts turning the main trimmer goes to the low side and releases the working jib sheet as the headsail luffs. This makes sure there is space for the trimmers and tailer who otherwise often pin the main trimmer highside.
    • Tailer: Start aggresively tailing, watching the clew position, when it reaches "just the right place" [which for a #1 headsail is around the shrouds on the new side and before the sail starts to fill] the tailer launches themselves to the new high side taking the line with them and continues applying pressure from the high side. If timed correctly this pulls the sail inside the lifelines and leaves it in about the power position. Thinking about it we should mark the lines so this is can be done consistently.
    • Grinder: Grind the drum as fast as possible, this makes sure overrides spin out and means there is no pause between tailing and trimming.
    • Bow: Skirt
    • Main: Bring the traveller up to the new side. Wait until the sail fills and then let a little sheet out (unless in strong winds) as the helm drives down to meet the headsail's power position. Use the fine tune to let this sheet out.
    • Helm: Drive down a little (sail to the headsail in it's power position)
    • Grinder: The grinder becomes the trimmer. We're looking for the head of the sail to be about a hands width outside the top spreader for the initial power position. 
  • Recovery
    • Trimmer: As speed builds (>5 knots) starts letting the jib lead come back to the pointing position, about #3 for the crappy headsail, perhaps #1 for the good sail. At the same time trim in further until the base is close to the shrouds and the top of the sail just about touching the shrouds. In low winds the tailer can manage the jib lead while the trimmer trims in the headsail to its final pointing position.
    • Helm: Bring the boat up as the headsail changes to its pointing positions
    • Main: Bring the fine tune in to close the leech and drive the boat up.
    • Main: As speed builds pull the backstay back on

The backbone of a good tack here is - start with full wraps on the winch and the handle in. Spin that handle and the grinder goes straight into trim mode.

Modifications
  • Light winds
    • Roll tacking, pit forwards shifts weight low at the start of the turn to help the boat around, swaps back to the original side (now the low side) as the sails fill and shift back high side to bring the boat back upwards.
    • Leave the sails a bit deeper, leave the jib lead forwards closer to the power position
  • Really light winds - just trying to get the boat moving.
    • Perhaps flatten the sails again
    • Take up another sport
  • Strong winds
    • Go straight to pointing trim rather than fighting the under powered jib lead (we're going to beef these up a bit but likely still a bit underpowered). Not roll tacking, weight goes highside and hikes as hard as possible
  • Waves
    • Trim: Leave a bit more twist in the main sails, don't sheet in quite so hard.
    • Helm: Time the tack so the next wave helps pull the bow down on the new side
  • Single handed
    • With autopilot:
      • Lock main traveller, get both jib sheets in hand
      • Trigger tack on AP (-1&-10 or +1&+10).
      • Sheet like mad to power position
      • Trim main quickly
      • Adjust AP to get sails pulling
      • Start fine tuning
      • Get back on helm and sail to the wind
    • Without autopilot
      • Same as above but using the wheel lock and stopping the tack from in front of the wheel