Here is a link to a thread where I found instruction on how to replace the batteries in an Oceanic DataMax depth gauge/bottom timer. Just as advertise I brought the cool instrument back to life.
http://www.scubaboard.com/forums/co...s/59844-oceanic-datamax-ii-2.html#post4208382
couv
http://www.scubaboard.com/forums/co...s/59844-oceanic-datamax-ii-2.html#post4208382
couv