Problem (ALSO!) with sounder - which is the best portable one?

[petem]

Good idea to check the liquid.

The Airmar recommendation is to stick the housing down with silicon sealant and use Propylene Glycol [Try Ebay] as the coupling liquid. In principle any liquid will work, but I think mineral oils are not good for the silicon sealant, and vegetable oils can turn rancid given enough time. Water obviously might freeze. I think propylene glycol is less toxic than ethylene glycol, hence their recommendation.

I would doubt that enough micro-air bubbles could be introduced by removal and re-coating to prevent the signal transmission.

I was going to ask how I might be losing liquid but perhaps I have a very small leak. I'll need to investigate next time.

Incidentally, I believe that when the depth is flashing on my tridata display, it means that the depth cannot be determined. Any idea what causes this? It does it quite often for maybe 10-20 seconds at a time, even at rest.