you can also look out for increased fuel consumption (fuel leak), periscope malfunctions in the form of blurred vision out the scope, compressed air leaks, guns not working etc etc.
or you might go through a mission and never have a problem.
You can go to SH3 commander when you close SH3 and disable malfunctions and sabotage and then reload SH3. problem solved.
this is just an added realism portion of SH3 commander.
emjoy!
