I practiced the searching and mapping techniques with the compass and the light last evening by myself, Yup, Alone It was awesome dive.
As to the compass, I agree that the compass should be recalibrated every use for the assurance. I dont spend that much time this computer yet due to the horrible weather. So, I cant give any thoughtful review, but there are some cons (please correct me if I miss something from the manual).
1. A relative short period display: without pushing up or down button, the display time in the compass mode is only about one minute. So, you have to push the select button every minute to keep the compass mode, even after locking a bearing. Of course, this shortcoming is only applied to some types of diving. Maybe, I expected too much for the scientific diving purpose.
2. Like any other analog (?) compasses, the digital compass MUST be located on the horizontal level. Otherwise, it shows the reverse (180 degree) direction. It might be ok after getting used to do it. LOL, it is $1775 computer.
3. Unlike the ordinary compass, the right direction of compass is only seen in direct the above the computer, not staying ahead of head. Again, if you break the horizontal level, the direction is in the reverse way. This part was a really PITA to me.
4. When push select button to engage the compass, it should be long push. Otherwise, one push button engages the Bookmark function in your diving mode. Yeah, it was another pain with 5 mm glove. Accidentally, I created unintentional seven bookmarks.
Thats it.
Dont forget. It is only about the digital computer feature. I dont find any complaints yet except the lack of gas switching feature in underwater.