Sunday, March 26, 2006

Anchor Track





The other night we had a little excitement. A cold front passed through arount 2100. Libby and I were on the forward deck watching a movie on the laptop when thunder and lightning started suddenly. We scrambled to go below as a very fast moving wall cloud approached.

In the next half hour or so we got blown around pretty good. You can see on the picture from our GPS. The purple line on the GPS is the locus (track, bread crumb trail) of our motions during the storm. The locus is a circle with a radius of 100 feet. The center is where our main anchor sits. We have 80 feet of chain out. Why is the radius 100 feet rather than 80 feet? That's an exercise for the reader.

The little anchor symbol is the reference point for our anchor dragging alarm. In theory, it should be at the center of the circle and the alarm should go off if we move more than 100 feet or so from the center. In practice it's hard to get the alarm centered correctly and I allow 300 feet before alarming. Another exercise for the reader. Why 300 feet rather than 100 or 150?

We also have a second anchor out. Since we went around in circles, the two anchor rodes are now twisted around each other.

Another boat reported seeing two waterspouts over the harbor as the wall cloud passes. Wow! That's scary.

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