Vapor Detectors with Blower Control?

[TooCoys]

We've finally made the decision to move aboard, and it's a gas engine boat.

BUT WAIT!! Before you go into "gas goes boom", and "I'd never own a gas powered boat", let me say that this IS NOT what this thread is about. That's a dead horse that's been beaten to a pulp, rotted, resurrected, and beaten again.

When installing a vapor detector for a live aboard boat, is it safer to have automatic blower control or not? The reason that I ask is that it seems to me that if the sensor goes off, having automatic switches (current/sparks) could automatically ignite the vapors.

So is it safer to have auto switching of the blower, or manual switches only that way you can exit the cabin and operate the blower remotely?