Our company deals with weather tight sealing and in most cases, it is virtually impossible to completely seal a volume of gas(air). It will find a way of venting and sucking in. I know we all try very hard to seal our boats to the n'th degree but sealing good enough to cause a structural failure is, well, I don't know how to do it. The largest concern I would have is the venting/inflating of the compartment causing a pumping action that will fill it with liquid. Like you said, go ahead and pick the location that will vent. You don't want it low in the boat where it can suc up water!