Not all countries require a license
for the skipper
to "pass through", but they still clear customs
and immigration like anyone else plus you are a business not a pleasure boat. Each country has it's own rules.
When a license
is required as in US waters it all goes away once you leave and enter international waters. The paper no longer means anything (sort of).
What is unstated in your question is "Can I get insurance
for such activities?" The idea of being uninsured with any kind of venture opens you up to untold trouble even if losing everything you own may not be of concern. The criminal implications of the whole problem might place you in jail if you failed to have insurance
if anything happened. If you can satisfy the insurance company then you'll be almost all the way there. You really should draw up a business plan and sit down with an agent to help you figure out how you can make this all work.
Most countries will recognize an active USCG license but you may still need to apply and pay for one in another country if it might be required. As a commercial
vessel all the customs
immigration rules may also be slightly different than recreational boaters. All passengers will be required to be documented as well as the boat with additional rules for the crew. The operation of a business in multiple countries is not without a fair amount of paper work. I hate to say it but there is no one size fits all ports rule
. It's all one country at a time.
There are no rules for certain. They can all change. In the age of the war on terrorism many far away places are under political pressure to demonstrate that they are prepared too.