Andy, have some green! Thanks for taking the time to share your thoughts. I'm betting it's :"So. My guess is that either the flow is not set up right for your metabolism and actually exceed it, but that you likely burn more O2 on the descent."

I think I get jazzed up on the entry, especially with current diving where the art of current predictions always leaves one with a bit of uncertainty. The descent involves more fidgeting, particularly because my ears are apparently extremely sensative to the effects of squeeze and extra sensative to o2. Once at depth I chill out and get in the groove, prefer to be as still as possible. Now that i'm getting more comfortable staying down longer, I bet I need to turn down the flow. I'm betting my metabolism drops precipitously once I'm all dialed in and at a constant depth. Your explanation makes the most sense. I'll look into the other possibilities. None the less, a needle valve is still an attractive idea to me and you seem to be the biggest advocate of them. I'm tempted to ask you to go into more detail about the attributes of your needle valve. If you would be so kind, please wax poetic about it here or on another thread if you like. In any case I will be contacting you about the prospects of adding one to my set up... aside from the conversion issues, i'd need some training and am not sure what you'd require in that regard.

I hope you don't take offense that I opted to go with the copis, as the manufacturer is practically at my doorstep... I still hold a high regard for the Pelagian.