Passports are a global requirement for international travel, but their value varies depending on the holder’s country of origin. Passport privilege means that a Japanese national will have free roam over all continents, while someone from Afghanistan will likely be bared entry outright. Inequalities related to passport privilege means that many will face discrimination, and will be forced through a tiresome process of applying for a visa—all of which costs money, time, and energy. It is not fair. Everyone should be granted the same rights, but wishing thing to be different does little to alter reality. The best thing to do is to stay informed, and to be ready.
It is important to read about the formalities of each country before visiting, because applying for visas can take a lot of time. Some countries may grant a visa on arrival to certain passport holders, but never assume this, do your research.
Customs in certain countries (like new zealand or fiji) sometimes require an Advance Notice of Arrival. A failure to send this document before arriving might result in hefty fees. Most countries have designated ports of entry for visiting yachts, usually a port with a customs, immigration and quarantine office.
Upon arriving in the country, fly your yellow quarantine flag and proceed to the quarantine anchorage, or dock. In some cases, you might have to hail the Port Authority on VHF to announce your arrival. They will not allow you to touch land until you're properly checked in. Countries like New Zealand and Australia demand that your vessel's bottom be clean (they will require proof), to avoid introducing invasive species into its home waters.
Some countries will give visa extensions, but plan appropriately and apply long before it is set to expire. If your boat needs repairs, or cannot leave due to weather, you may be allowed a short extension (for a price).
Upon entry or departure, you may need to pay the immigration, customs, health and quarantine officers. These fees are documented, it is best to learn what prices to expect before arriving. We find Noonsite to be a good up-to-date ressource for country-specific information on fees, customs or quarantine procedures.