Well, it sounds like you better hope not! :^(
Depending on the country, you may not have any problems, or you may have your boat impounded or possibly confiscated, or you may wind up in jail for a very long time. In some parts of the world, possessing illegal drugs is punishable by DEATH!
Also, keep in mind that US laws and protection (if any) are of no value or importance in most other sovreign countries.
Do you really want to take that sort of risk?
~ Happy sails to you ~ _/) ~