I believe you need to enter your tank capacity and working pressure to get Oceanlog to calculate your SAC rate. I haven't tried the latest Oceanlog version (2.2.3 beta), but it would be nice if one could enter a default tank volume and working pressure so the SAC rate calculation is done when the dives are downloaded.
As for "crazy" data, I frequently experience that problem, especially with my older VT Pro computers. Starting and ending tank pressures are frequently incorrect, and I get some wild dive profiles that all appear to be caused by spurious data when downloading the dive (instantaneous depths to a couple hundred feet, dive durations of hours, etc.). I frequently find it necessary to delete the dive and re-download, being careful to not even look at the computer and holding my breath so there is absolutely no interference with the cable connection.
Thus far, downloading data from my Atom 2.0 has been reliable, although the temperature data is incorrect. I have some trouble with my wife's VT3, mainly due to the loose USB connection with my laptop, but it works fine on my desktop computer.
As for "crazy" data, I frequently experience that problem, especially with my older VT Pro computers. Starting and ending tank pressures are frequently incorrect, and I get some wild dive profiles that all appear to be caused by spurious data when downloading the dive (instantaneous depths to a couple hundred feet, dive durations of hours, etc.). I frequently find it necessary to delete the dive and re-download, being careful to not even look at the computer and holding my breath so there is absolutely no interference with the cable connection.
Thus far, downloading data from my Atom 2.0 has been reliable, although the temperature data is incorrect. I have some trouble with my wife's VT3, mainly due to the loose USB connection with my laptop, but it works fine on my desktop computer.