or dozens other mechanical 'what ifs', and you've stove in a nearby boat or a dock, or gone up on rocks. A few experienced people might feel more vulnerable relying solely on the boats mechanical systems for mooring, anchoring, or even passing through a tricky tickle of water like this harbor entrance(or say, Woods Hole Passage).

The boat under sail still has the fall back of starting the engine. The boat under power alone, has no immediate option, unless the sails are deployed.

And then there is losing steerage, which is a problem for either. Quick!-anchor(that's easy on all boats-not!)