Here on the East coast
the Customs folks are pretty reasonable in general. Depending on the specific port from which you wish to clear, 24 hours notice is often required. They will come down to your boat, fill in the papers and then expect you to shove off. If you have taken on fuel
for the trip, save your receipt and ask for a tax rebate form. Last time we cleared we got 38 cents/litre back.
The requirements for entering foreign countries vary widely, so some research
is useful*. A few other places now require advance notice of your arrival, and don't try to avoid this task. You will regret it! Some countries require a visa for each person on the boat, for some places this depends upon your nationality. Boat registration
papers, passports (of course), sometimes some form of insurance
(but not often as yet), and I believe that a few countries still require various inoculation certificates, but we've not had that question for years now in the SW Pacific. It will save you time if you have prepared a list of equipment
on board (electronics, engine
, outboards, dinghy
, other high value items) complete with serial
numbers. Many of the forms that are required ask for these things and it is hard to remember all that stuff. We've never been questioned about the accuracy of the list, nor had it checked on exit. The most significant thing is to be neatly dressed, show respect for the officials and for their country (and all it's inexplicable rules) and smile a lot. If you are relaxed and pleasant most likely they will be too. It can be an interesting and even enjoyable experience.
* About the research
... Noonsite is often way behind the times, and the rules change without warning, even here in Oz. Some nations have websites that list requirements, but those too may not be current
. Queries to consulates can be useful, but it is surprising how often their staff know little about small vessel clearance. Word of mouth around cruiser hangouts can help, as can specific requests for help on fora such as this, but honestly, it is a moving target and for small and infrequently visited places, good info is scarce.
Good luck with it, and remember that we all go through it. The first times are the hardest (or were for me) and then you kinda get the hang of it.