The theory was formed that any country on earth declares you inmediatly “illegal immigrant” if you touch land with a yacht without a customs officer present. Two days on shore without visit to immigration was titled “impossible and illegal worldwide” - i beg to differ…
It is not about “lawlessness” it is about “respect good neighborhood and trade customs” that are the base of the law of the seas. And stand far above nationalistic law bulleying in most countries, especially in such with a decent seafaring tradition. Nations built on the tradion of the Spanish Overseas Empire normally have such customs - most of the caribbean has them.
It is not about “avoiding and escaping” it is about “get respected as deserved” and “not get molested more than strictly neccessary” being a visitor bringing in money.
Good trade customs do not change with short living legal texts they have centuries of practical implementation and refinement. The freedom of the seas is based on good trade customs. Not national prohibistic xenofobic law enforcement.
A relaxed caribbean country, familar with yachts and tourism will have “enforcers that will hunt you down with kindness invite to stay” and interpret “inmediatly” as “within a month”, or “when you have time” but as said ealier, 2 days, a weekend, on a beach, is not “illigal imigration” for anybody with a “decent seafaring tradition and practice” when dealing with private yachts comming in from sea .
Get a boat, test it out - papermousing law text on internet doesn’t get you a realistic picture of the customs and realities of the seas.
The general idea about this stuff is : if he lives on a yacht he is obvioulsy not staying, if he is not staying immigration has no reason and no business to interfere in first place.