Yesterday my ST60 gave me some strange readings as a thunderstorm moved through. In the window it read "ddd", and an alarm was going off. I called Raymarine, and the tech said he had never heard of this. I haven't found anything in the owners manual either. There was a LOT of lightening in the area at the time, nothing hit to close, and we were not hit. This is part of the ST60 suite, and the other guages were working fine. Any ideas? Thanks John