Tony,
Can you proces your track data so it averages the speeds over 10 second intervals (even 30 second intervals).
I think that 17.1 knots topspeed for the duration of 1 second and 29 ft = 8.8 mtr is a bit short. Natural inaccuracy looks like a likely cause for this reading especially since 1 sec before you were doing 14 kn and 1 second after you were doing 13 kn. I feel it is unlikely that you can both accelerate from 14 to 17 and decellerate from 17 to 13 in the time span of 1 second. When looking at the spread of data in the provide track log this 17.1 kn speed really looks like an suspective outlier. It looks like you average about 13.5 kn over roughly 500 mtr.
Ofcourse the name of this "high score" game is best average over at least 10 seconds.
Topspeeds are always a bit doubtfull but exporting the GPS track to Excel showed I have 13 occurences of 16kts (without the spi), which accounts for a total of 180 meters or 00:01:07 minutes.
180 mtr / 1 min 7 second = on average 2.686 mtr/sec = 5,2 knots. Either you've made a typo or these 13 occurences are highly suspect.
So, if 16 knots is a "normal" speed I would say that the 17 knot topspeed is very real.
I'm convinced if I wasnt sailing in survival mode ;-) 20kts+ is possible.
I fully agree that 16 to 17 knots is a speed that most catamarans must be able to achieve in the right conditions. The newer cats even rather easily. However 20+ kn has proven to be very illusive. At least when looking at either 500 mtr legs or 10 seconds sustained speed. Many feel that these 4 to 3 knots is only a small gap to bridge but reality is showing that this 17 % to 25 % speed increase is rather large.
Of course the problem several us are finding is the seastate (survival mode as you call it) For 20+ we really need windforce 5 or more with very flat water. This is actually a rare combination of conditions. I'm looking for a good summer day with a very calm morning and a good heavy thermal wind that quickly builds from the land after noon. Not too gusty. So probably one only has an hour or so when the winds pick up to make the record. After that the water gets choppy and the gusts come through big and heavy.
Anyway, an hour later after I pitchpoled, poked some battens through the main, and blew the spi panels apart (Yes the glue let go!) I abandoned the race.
I'm sorry to hear that !
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(ps.Wouter, will you be there next year? ;-) )
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Was looking to be there this year but I didn't want to do it solo. Just took my new crew out today. Little lady of 55 kg with a big heart and guts that is the envy of many guys. Was bloody windy today as you most likely know. If she stays than I'm considering doing this race next year.
Did you participate in the voorjaarsbokaal at Almeerderstrand this year Tony ? If so than I know who you are.
Complete GPS track available upon request...
(Garmin's Foretrex 201 rocks!)
Ain't that the truth !
Hey guys ? Any US or Aussie sailors in for a "best GPS average over 10 seconds" high score game ?
Wouter