Behind the trim on the aft of the keel box is a double length of shock cord that is supposed to tension the string. To get at it you have to remove the table then the fibreglass trim. If you need to replace shock cord, 6mm surgical silicone tubing makes a much better and more durable spring.

If you get fed up with the whole horrible DATATEK system there are better ways of monitoring the keel position. I have just replaced whole set up using commercially available parts. I am confident that this will be a lot more robust at both keel and helm ends. I am happy to share what I have developed if anyone wants to get in touch. Martin Hargreaves 335/50

Hello Martin
Thanks for the information , I have got the Datatek working again with a spare tranducer I had , but I think it is only a matter of time before the transducer is destroyed again as the cord is bound to slip.Loading the potentiometer bearing cannot be a very good idea. When it goes next time I think I will just put in a "string pot " maybe more expensive but no need to messs with the trim.

Jan

Yes - a string pot is certainly a good way to go but I was a bit taken aback by the cost on one which would be expected to survive in the keel box!