The US is the only country I'm aware of where you can carry a gun aboard your own boat.
The US is not much better for those not citizens of the US, meaning it really is no different as a nation. Foriegn vessels cannot simply import weapons into the US by having them on thier vessel.
Some other nations will allow thier own citizens to have weapons on thier vessels. So the US really sets no unique example.
A few nations friendly to firearms just changed recently.
Yemen for example was very friendly towards small arms until earlier this year. Now the government is extremely anti-gun. Almost a complete reversal.
Yemen if you look at a map is just on the other side of the Gulf of Aden, across from Somalia.
A coincidence?
If you were a vessel traveling through the Gulf of Aden, and you chose to be well armed, entering ports in Yemen should have been no problem.
Now that has changed, with Yemen seeing international pressure to crack down heavily on legal gun ownership. The government has responded by doing exactly that. It has gone from a place with more firearm freedoms than even the US, to practicly outlawing arms, and arms dealing altogether this year.
The number of ports a private vessel with arms could enter decreased further.
Europe and even antis in the US are hard at work increasing gun control laws and attitudes throughout the world.
Gun rights groups should be just as diligent. The UN has also been drafting many laws, and has influenced the US gun laws significantly. ITAR restrictions stem directly from UN pressures.
ITAR restrictions are then enforfed by the ATF.
(Small arms restrictions really are a strong abuse of ITAR, as it was imposed to allow restriction of things like classified material.)