DiveNav on your side-by-side comparison you need to change the user changeable battery to not user changeable and they are only using a 1/2 dot matrix screen.
http://www.scubaboard.com/forums/oceanic/356499-need-help-oc1-o-ring.html
http://www.scubaboard.com/forums/oceanic/356499-need-help-oc1-o-ring.html