Navigational Error

A new buddy (experienced, but never dived together before) and I swam to 1200 feet to survey a passage. Once we dropped stages and made it through the first restriction, we began to survey upstream....we came to a 'T' in the line, marked it properly, and continued surveying upstream. Buddy signals me that she feels "sick", and being a firm believer that all should be "go" to be in a cave, we called the dive due to her feeling "funny".

The end result was that she had some CO2 build up (headache aferwards) and some narcosis (we were in 120 feet of water) which contrinuted to this nausea. What happened next was disturbing. As I placed a marker on the line to indicate the survey end, I turn around and she is GONE. Vis is about 10 feet at this point. I make the T, and ASSUMING the other diver has made the junction and waiting at the main line....I look right and left.....and PULL the marker. I swim back out and toward the main line, and experience grabs me and says "This tunnel (that we just came in) does not look travelled"....I figure I will make the main line and at least confirm my buddy is not there first, but I am already thinking "went the wrong way".....I make the main line, no buddy.

I turn around to push back through the restriction to initiate a search, and come back to the T of confusion. At this point something hits my primary light toggle and it dies.....PROVING to me that things happen in multiples. I finally see her light downstream, somewhat confused as to where she is. I signal to her the way out. Bottom line, she swam right past the T, and went downstream. I assumed she had made the T, and therefore inadvertantly pulled the marker, leaving her NO ROADSIGN.

I was inimately familiar with the cave and she was NOT. We exited without further event. This was not a life and death situation, but it was concerning for about 4 minutes, and COULD have been a lot worse. Her experience guided her based on water flow and sediment.