I'm leaving on Thursday for a liveaboard trip. I have a spare battery for my Veo 3.0 in my save-a-dive kit, but I'm looking at the manual and it says to put in a new o-ring as well. That makes sense, but I don't have a new o-ring in my kit and if the lds doesn't have any then it's not likely I'd be able to get one before I leave. I'm also seeing annual replacement is recommended... the computer was purchased less than a year ago (July '11) and the log shows only 18 hours of dive time. I'm not too worried about the battery dying on the trip, but if I have to change it and I don't have a new o-ring, can I get away with putting the old one back if I'm careful in removing it?
I'm not asking "do I need the o-ring?" I'm asking "am I screwed if need to change the battery but don't have a new o-ring?"