DSK wrote:

Navigator wrote:

I've noticed something strange. I had suspected it for sometime but
just a little while ago my suspicion was confirmed. We had sailed to a
small island and moored in the only cove. Chart indicated no hazards,
just sand with small shell bottom. Dropped the anchor (Sarka) in about
4m of water and laid out about 6:1 rode as per usual.


Is "sarka" a type of anchor?

Yes it is.

How much scope do you let out to set the
anchor?


Well, it depends on the depth. My rule is not less than 4:1. Often use
6:1 and if it's going to blow let out more still (combination rode).


.. The depth under the keel indicated 5m. Went to bed. During the
night I woke up with a strange feeling of uncertainty. Perhaps the
boat's motion had changed but nothing obvious. Peering into the
blackness, the loom against the stars indicated we had not moved.


??? Dang you're good, doing celestial navigation to within a couple of
meters by eyeball through the port.

Why didn't you take a bearing, or better a transit, on some fixed
objects on shore? That way you can really tell for sure if you've moved
outside your swing circle.


... Nevertheless, the feeling did not go away. I flipped on the depth
sounder and it read 4m but then started to chnage -then 3.5 then 3.0
then 2.5 and that is when I reached for the engine key. But it stopped
rising at 2.3 and we need 1.8m.


I thought you said your depth sounder indicated depth under the keel?


Typo -it's always reading depth under transducer.

Cheers