Friday, April 7, 2017

4/7/17 Report - Rosary From Atocha. When Objects Move Against The Current. Erosion This Morning.

Written by the TreasureGuide for the exclusive use of

Atocha Rosary In Sedwick Auction.

There are tons of coins listed in the most recent Sedwick auction.  You can get everything from -escudos to lots of 12 half reales.

There aren't too many shipwreck artifacts in the auction, but this is one of the stars.  It has been shown in museums and magazines.  It is an early Atocha find and has an auction estimate of $25,000 to $50,000.

Here is the link.


I gave you a little puzzle a few days ago.  I asked if you could imagine when an object might be moved in the opposite direction of the current.  Here is one answer that has been experimentally demonstrated.  I don't know if I can find the video of the demonstration, so I'll just try to illustrate what happened with a simple drawing.

The illustration shows a submerged sand slope (black) with an object (blue) resting on the slope.  The current is coming in and up the slope (orange arrow).  What happened in the demonstration video in which the actual object was part of a plane fuselage is that the current quickly moved sand from around the front of the object.  When a sufficient amount of sand was removed on the lower side of the object, the object slipped down the slope.  The object did not slide down the slope smoothly but but in quick short steps.

Enough sand would be removed so that the object would slip and stop.  Then when enough sand had been moved again the object would slip down again.  This happened repeatedly as the object moved down the slope against the current.

This is a good illustration showing two forces (water and gravity) acting on two objects (sand and the other object).  It illustrates something I talk a lot about - trigger points.  The trigger point for sand was exceeded, but not the object.  The movement of sand resulted in the object moving against the current.

In this example, the force of the water was enough to move the sand, but not the other object.  If the force had been strong enough to move both the sand and the object up the hill, the results would have been very different.  After the sand that was supporting the other object was moved, gravity brought the object down the hill against the current.


Since the wind changed, there is just a little erosion on a few beaches but nothing very significant.

A Bit of Erosion at John Brooks This Afternoon.

Happy hunting,