Berkeley sensor worse than ever!

jwallace · Joined: 09 May 1998 Posts: 124 Location: SF Bay Area

I've known for at least a season or two to subtract 3-5 mph. But now it's got to be nearly 8-10 mph off! Yesterday it said solid 20 with gusts b/w 23-25. Folks at the restaurant, including myself, were just slogging.

iWinsurf, WTF?

windsrf · Joined: 01 May 1998 Posts: 464

I expect part of the problem has always been altitude of the sensor (where it needs to be due to other interferences though). However, I'm in general agreement with your observation - plus also believe direction is a bit off. Although direction may be accurate and this is just weird wind season. Would be interesting to hear how often sensors are recalibrated for example.

carl · Joined: 25 Feb 1997 Posts: 2674 Location: SF bay area

You need to send Iwindsurf a direct email to get action on a sensor.
They have said before that they don't read all these forum posts.

I don't think they recalibrate unless they hear of problems.

I have seen seagulls try to land on the sensor (actually pretty funny).
That may be contributing to calibration problems.

mez32522 · Joined: 28 Aug 2008 Posts: 26

5.0 yesterday with 99 liter freeride, planing 90%, but 145 lbs.
Today, 5.4 and 84, planing 97% so far, I've been in and out 4 times since 2:30.

johnl · Joined: 05 Jun 1994 Posts: 1330 Location: Hood River OR

Well is the 20 - 21 mph average they are claiming today (Tuesday) right? I was going to go there, but didn't trust the reading so I went to Isabel at 17mph ave. Well Isabel had maybe 10 on the water and then died to nothing. So maybe Berkeley was better??

foiled_again · Joined: 16 Mar 2001 Posts: 33

Hs Lordships was very good today. Strong wind and large, for Berkeley, swell. No seagulls sitting on the roof. Few windsurfers, one kiter, great session.

mac · Posted: Tue Aug 17, 2010 9:35 pm Post subject:

Remember that the sensor is at the BYC, up high, and it is generally windier upwind and north of the pier. I find it pretty accurate for wind above the break in the pier on the south side, and sometimes lower than wind in the circle.

windsrf · Joined: 01 May 1998 Posts: 464

Probably true, but majority of non-formula sailors don't typically inhabit those areas, at least if by "above the break" you mean west of the break? Thus our ongoing concern with the proposed ferry terminal and breakwater(s) -- had to work that in!

mez32522 · Joined: 28 Aug 2008 Posts: 26

Berkeley's lulls filled in around 4 on Tuesday, the reason being the wind was switching from WSW to SW, and the switch is always tough for us windsurfers to figure out. I've been windsurfing full time for 28 years, so no problem.
After my 3:45 log in as Mez, solid 5.4 and 84FSW, right up to full powered til 5:45, then quick die off.
Call it what you want, but early sesh's, maybe 16-22, then solid 17-24 after 4.
Yes, I'm a lightweight, but can usually handle a 5.4 sail up to around 20-28mph with no problems, and get onto a plane around 16 with judicious pumping, and I"m one of the best at that.

tomg · Joined: 10 Apr 2000 Posts: 294

Back in July I told iWindsurf folks about this problem with as scientific evidence as possible in this sport: identical equipment used on two days, one at H's Lordships and the next day at Pt. Isabel -with results that totally contradicted the wind graphs (what good are these sensors then?).

On that day, and many other days that I've launched there, the Berkeley sensor was reading way too high, but it did feel quite windy in the parking lot. My theory is that the air gets jacked up as it is forced up on to land.

The solution is to relocate the sensor to the fishing pier, like they did for the Crissy sensor which I'm sure is much more accurate now that it sits offshore.

Tom G.