[johnchute]

I have a 1976 Cal 27 sailboat. The depth sounder is off by a foot and half. I want to recalibrate the sounder so that it reads true. Does anyone have any suggestions as to how to go about this??

The depth sounder is a "Standard Communications Corp., New Zealand," "Horizon Depth," model "DS45."

Look forward to your suggestions.

Thanks very much,

Jack Chute