All laws repugnant to the Constitution are null and void. Yes, that very much includes the 4th Amendment.
There are two and only two distinct possibilies:
1. This boat was within the bounderies of US coastal waters, in which a warrant is required.
2. This boat was not within the bounderies of US coastal waters, in which case this was a simple act of piracy.
Today's reality? SCOTUS is "constitutionally challenged", wrote a sickening opinion, and now most of the difference of boating off the US and boating off some third world pisshole is the uniform of the guy pointing a gun at you while his palls ransack your property.
They have been doing it since prohibition
The courts have held that the Revenue Cutter Service (established by Alexander Hamilton) has this authority ever since the first smuggler whined that his rights were violated, which was right after the first board and search, which was right after Hamilton established the Revenue Cutter Service.
In other words, the Founding Fathers very much disagreed with you on this one.
Read the article, the fool CONSENTED to being searched.
You obviously have a problem with authority. Coast Guard members don't ransack property. This wasn't even mentioned in the goofy article/story. Are warrants required? Why are you so upset about our CG doing what it is supposeed to do? Would you have been upset if the CG found a hidden compartment full of smuggled humans destined for the slave trade? They rescued over 9,000 people since last October alone! And, how about drugs? They intercepted more than 150,000 pound of cocaine on the Pacific side alone. Yes, that was pounds.
Here are some statistics for you to digest before you lose your composure again:
The second link is straight to the USCG for statistics on smuggling people.
Here is a link to the drug statistics: http://www.uscg.mil/hq/g-o/g-opl/Drugs/Statswww.htm
Enjoy the reading and let me know if you need more information to help you form your thoughts a little more clearly.
I normally agree with property rights, but boats aren't like my home- they serve recreational and transportation needs only. Simply choosing to live on a boat doesn't change that.