Thank you for the prompt reply.
Protective sheet - I think you may be correct. What seemed to be a scratch appears to have gone?
NDL - Voodoo has worked for me for the last 15+ years. It just surprised me how quickly the NDL went down. My "normal" dive plan is swim around until I have a few minutes of deco then come up. The deco doesn't normally go down as much on the way up. Guess I'll need a new plan.
3) Conservatism - Yes I was planning to start off quite conservative, I'm old & fat, although not as fat as I was. Yet the OSTC got me out of the water quicker than the Vytec with no conservatism. I did some modelling on Suunto DM and Subsurface to see what worked out about the same. I may try 50/70 to get shallower even quicker.
OSTC PLUS 15643