agrimsrud said:Anonymous said:
I do take the time to figure out with both help from the guys on the dock and my own eyes and mask what the reading would be when we touch bottom. That is all you really need for BVI anchorages and navigation.
Funny. I wasn't planning on using the hand held for anything other than the initial calibration. I'll stick it in the water and compare it with the depth finder on the boat. And either recalibrate it or just note how far off it is. A line with a rock on the end and a measuring tape will do the same. But I have the hand held so why not bring it? I guess my point was, in answer to the newbie question was that you should not trust the depth finder on the boat. A couple of years ago we had a Sunsail boat. Didn't notice until we had left the dock that the depth finder was reading 100 feet. That's a pretty important (most important?) instrument and it needs to be useful.
What I really want to know is what the sounder says just before or when the keel touches. You can find a soft clean sandy spot and check by braille.
Or you can do you own bottom safety check in shallow clear water to get an idea what the unit reads with say one foot under the keel. The bright sandy bottom will give you better light to look at the bottom anyway.
Usually the better talent on the dock can tell you what the sounder will say with no water under the boat.
