12MB PDF - Association for Mexican Cave Studies

current made it impossible to continue.The cave was, however, loadedwith pottery, small figurines andbones, which greatly excited Dan,our expedition archaeologist. Thehigh altitude made our decompressioninteresting since the standard U.S.Navy decompression tables and correspondingstop depths had to be modifiedconsiderably.Nacimiento del Rio VerdeWhile the others logged divesin Media Luna the next day, Paul andI amused ourselves free diving inthe spring basin until I surfacedunusually dizzy after a dive to 21meters and decided that there maybe something about holding one'sbreath at altitude that isn't healthy.Accordingly, we spent therest of the day looking for thissmall spring, which definitely wasn'tworth it. Any cave at thissmall, shallow nacimiento will definitelyrequire extensive excavation.Nacimiento VerdeOn the way from Valles to RioVerde we had crossed an unusuallyclear stream, so we stopped on the wayback and repeated for the umpteenthtime the only Spanish we knew,"l.Donde esta el nacimiento?" ­("Where is the spring? ") . To our delightwe learned that the springwas less than 0.5 kilometer fromthe highway, at the base of a nicehill. Accordingly, while the restof us went off to the R!o Huichihuayan,Ken, Frank and Terry madedive #18 here, penetrating 262 metersto a depth of 47 meters. On dive #21the next day they extended exploration27 meters further, ascending toa depth of 27.meters. Even thoughthe visibility here was only 3-5meters and the temperature 23°C,this locale is very interesting inthat it is one of the few s.ites investigatedthat shows some promiseof coming up into air withinthe range of cave divers.Nacimiento del Rio HuichihuayanJamie and Carol did the honorshere with single tanks, attemptingon dives #16 and 17 to find a routethrough the cave wreckage at thehead of this picturesque river. Unfortunately,they were unable toprocede further than 30 meters underwateror deeper than 9 meters,though Jamie did report that at onepoint he might have been able tocontinue further if he had removedhis tank. This spot also had thecoolest water that we dived in thewhole trip, l8°C, which struck usas odd because it was also thesouthernmost site visited.26