I have three different programs that can read the FIT files from the Mk1: Subsurface, MacDive and Diving Log 6.0. I'm working on a project to compare the NDL data between a few computers and notice that the format has changed between 2.60 and 4.00.
Prior to 4.00 the NDL numbers ranged between 99 and 0. This was pretty straight forward as it was in minutes.
After it appears to go from 999 to 0 but I'm not sure if this is minutes. Comparing with my Perdix for the same dive it seems to be close enough for most dives but for some it is out by quite a bit.
It seems odd to store an NDL of more that 99 minutes if that is all that is displayed.