Skip to Content


Sally Sells Seashells

A cache by cachbefound Send Message to Owner Message this owner
Hidden : 06/09/2012
3 out of 5
2.5 out of 5

Size: Size: other (other)

Join now to view geocache location details. It's free!


How Geocaching Works

Please note Use of services is subject to the terms and conditions in our disclaimer.

Geocache Description:

The cache is not at the posted coordinates.

Sally sells seashells by the seashore...   Of course many know about Sally selling seashells by the seashore but few know just how successful she is.   Well I know Sally and I know the secrets of her seashore seashell selling success.   When I first met Sally her prices were from one to nine dollars, she sold limited quantities and she only displayed no more than nine seashells at one time in the three by three arrangement shown below.   When she sold a shell she would replace the shell with one of equal value.   She had worked out an optimal arrangement, according to price, that maximized her sales.


I watched her selling seashells over the course of an afternoon and here is what I observed.   A young man bought the three seashells from the center column, paying with 15 one-dollar bills.   The same young man came back minutes later and bought the three seashells from the center row and again he paid with 15 one-dollar bills.   A short time later a young woman bought three seashells from the diagonal, top left to bottom right.   She paid with a twenty and received three dollars in change.   Before leaving she decided to buy the other diagonal, bottom left to top right and paid 13 dollars.   It went on like this all afternoon with most people buying two or more seashells and in many cases returning to buy more.   At one point a distinguished man in a white suit and a Panama hat came up to see Sally's seashells.   Sally immediately greeted him with, "Hello doctor Sebring, I'm so glad you could finally drop by."   The man studied Sally's display for a few minutes before asking, "Why didn't you place the four primes in their obvious location?"   The man went on, "You've got two primes in the left column, two in the center column and two in the bottom row, it just doesn't make sense to me."   After a few seconds Sally said, "But doctor look at the arrangement as a string of nine digits."  The doctor again studied Sally's display for a few more minutes before exclaiming, "Oh now I get it, the digit sequence was selected for its polydivisibilty property."   "That's correct but it's not by design, I just discovered it as the best arrangement after many months of trial and error", replied Sally.

  • After you discover the nine digit sequence, top row followed by center and bottom rows, use it as the keyword in certitude to receive the cache location.
  • The terrain rating is based on exposure to high wind and flying sea foam conditions.
  • Access to the cache is limited from 8:00 to sunset.
  • Please use stealth and care when retrieving and returning the cache.
  • Final location updated: 10/25/14

Validate your solution with certitude.

First To Solve
First To Find


Additional Hints (Decrypt)

[hide: Behind second deck support, starboard side as you face the sea. ]

Decryption Key


(letter above equals below, and vice versa)



93 Logged Visits

Found it 69     Didn't find it 9     Write note 7     Temporarily Disable Listing 3     Enable Listing 3     Publish Listing 1     Owner Maintenance 1     

View Logbook | View the Image Gallery of 7 images

**Warning! Spoilers may be included in the descriptions or links.

Current Time:
Last Updated:
Rendered From:Unknown
Coordinates are in the WGS84 datum

Return to the Top of the Page

Reviewer notes

Use this space to describe your geocache location, container, and how it's hidden to your reviewer. If you've made changes, tell the reviewer what changes you made. The more they know, the easier it is for them to publish your geocache. This note will not be visible to the public when your geocache is published.