I like what I'm hearing, as I am an instructor & frequently do decompression diving at the end of the day, after working with the students. This mode could be very helpful. Just 1 more question, I run my Petrels on the VPM for my technical diving & the info on the recreational mode states it is based upon the Buhlmann ZHL-16C algorithm. Are these compatible? Or will it run the NDL's off the VPM? Just curious, as I like to have the VPM & use V-planner tables for back-up for technical diving. Does the computer switch back & forth with consideration for both algorithms when it comes to tissue loading & decompression needs? Thank you for the insight, Bruce.