2016 Calibration weekend

February 28, 2016

Leen, Floris, Joost N and myself arrived Thursday evening in West Cowes. At Pier View Sue and her Staff had already lightened the fireplace, so we could have a nice warm English beer.

When we arrived at Berthon’s on Friday, we found a brand new WINSOME. She looks great!

Berthon finished some last jobs and we prepared WINSOME by installing the main. We had a test run with the engine and everything seemed to work fine.

Back at WINSOME’s cottage Brenda joined us for a drink and a little bit later Laura arrived.

On Saturday morning we took Luna again to Lymington and found Campell Field fresh, salted and tainted  from the Caribbean 600.

Although circumstances were not ideal for calibrating Campbell managed to calibrate the new peddle weel speedometer up to 1% accurate (changed value from 4.4 to 4.29 Hrtz/knot).

Thereafter we preformed a compass swing, and the B&G instruments gave us a ‘PASS’. Heading offset was changed from +002 t0 -003.

After which we did some serious upwind tacking in 22kts calibrating the Apparent Wind Angles. When they seemed equal on P and S tack, Campbell corrected the Leeway, which now is around 4 degrees.

Thereafter a True Wind Speed and Direction correction table were made.

The main problem that was not solved by the end of the day, was the fact that the Heading seemed to be off every now and then. We showed Campbell our B&G H3000 compass, a model which he had not encountered before. We wondered wether there might be a structural problem with the compass.

Replacing it by 100.ooo GBP gyro compass would definitely solve those problem, but also create some others. Most practically, a power shut down would lead to a 3 hour restarting process (only possible in a harbour) and WINSOME would have to turn into a heavy Fort Knox to protect this Koh-I-Noor like compass.

We decided to check with B&G to find out if they have any known structural problems with this type of compass and see if replacing it by another fluxgate compass would solve part of the problem.

Campbell explained to us how we can send him our log files, so he can analyse our performances in the future and advise on how to adjust some of the calibrations in the near future.

Finally Laura, Leen and myself took WINSOME back to East Cowes, while Floris and Joost N took Luna.

Unfortunately today conditions are equally bad for calibrating. On top of that, we found out that the prop-shaft is leaking. Over night we figured that around 10 L of water entered WINSOME. Leen had a look around the boat and found that water was dripping from the prop-shaft. Therefore it is unsafe to leave WINSOME at East Cowes.

I checked tho compass at the Steering weel showing 181 and the B&G heading showing 161. Therefore we should look into the compass problem a little further.

Joost and Leen will take WINSOME back to Berthon this afternoon and speak with Robin on Monday morning with the following to do list:


-Solve leaking along the prop shaft (Berthon).

-Solve the Voltage instrument on the PC battery (not showing any measurements, Berthon).

-Find out wether the Heading issue is a hardware problem an could be solved by replacing the B&G H3000 (B&G Lymington though Berthon).

-Check AIS, as WINSOME cannot be seen on LUNA’s display while other boats can be seen (Berthon).


To finish of with a positive note:

We managed to get equal boat speeds on both tacks.

We managed to get equal AWA on both tacks.

We managed to get an accurate boat speel unto 1%.

We calibrated correction tables for TWD and TWS and Leeway.

We learned a lot on how to improve in the future.

We know our weakest points.


Thank you Campbell for all the input, thank you Harry for organising and thank you to Leen, Floris, Laura and Joost for all the work, good company and a nice weekend.

All the best!



Post by Boj | February 28, 2016 |