Thanks again Mike, i havent quite finished the cave book yet, but getting through it slowly!! Questions just came up in my head when i read Mark's story. I understand what you are saying, most of it is common sense, but until people start thinking about it a bit, its not so common sense if you know what i mean. I have looked around a little on CDF, but i know there is more on there than my brief checkout has shown me. Also i understand there is no hard and fast definate way of dealing with some of these kinds of occurances, just asking advice and what you and others might do in that kind of situation.