selves were two blackened, hollow, cylindrical sticks of 

 coral sand, for the metal barrels of the guns had com- 

 pletely disintegrated due to the corrosive action of the salt 

 water over the years. The detector also led them to a brass 

 door lock and, surprisingly, nearby, a large, heavy key. 



The second day. Bill climbed on deck from a trip to 

 the bottom, and after he had removed his face mask, 

 reached into his breast pocket and carefully brought forth 

 a small piece of coral. He showed it to Ethel and me 

 proudly. 



"I'm pretty sure it's something valuable — maybe a 

 piece of jewelry," he said. "The metal detector picked it 

 up, and I dug it out from deep down in the sand with my 

 hands. After I discovered how small it was, I didn't dare 

 use any digging tools." 



He placed it in a china cup from the galley and 

 poured acetic acid over it. This would dissolve the coral 

 composition covering it without damaging the object it- 

 self, he said. All through our lunch hour we eyed it curi- 

 ously. What would it prove to be? 



By late afternoon, when we were on our way back to 

 Marathon, Bill could wait no longer to find out. Carefully 

 tapping at the coral with the handle of a screw driver, and 

 rubbing it with his fingers to loosen it, he finally succeeded 

 in uncovering the object which it enclosed. 



To his chagrin and our unkind laughter, it turned out 

 to be the key of a Spam can, tightly wound with a strip 

 of tin, as it had come from the can. We thus learned that 

 under salutary conditions it does not take very long for 

 coral encrustation to form on a metal object underwater. 



Indeed, Ed's metal detector worked so successfully 

 that much of the time the men found themselves digging 

 beneath the sand only to uncover a variety of beer cans 

 discarded by thirsty fishemien as they trolled about tlie 

 reef in their boats. Unfortunately, there was no dial on 



70 Sea Diver 



