Sailboat Living for Survival

A couple that did it

Financial reasons - if you pay rent or a high mortgage and now can find a Marina where you can park your boat and live in it then you can compare costs.

Safety - you have to balance this with the security of living on land and the risks of doing anything out on the water much less traveling and living there.

Lifestyle - home is wherever you happen to be when it comes to living on a boat.  In the case of this couple they have jobs so don't seem to have any travel plans.

Post Collapse - I see some benefit of being able to bug out to the water but keep in mind that your safety is relative to the threats that exist.   Piracy still exists and you should know where you are going.