To temporarily import a boat to Mexico, you will need to bring its title, proof of citizenship, and the departure clearance from the foreign port where you set sail. (If you are bringing your boat by land with a trailer, you will also need the title for the trailer.) Once you arrive at your destination in Mexico, you need to solicit an FMM (tourist card) from immigration, and then get a temporary vehicle permit for your boat. With your FMM, the title for the vessel, and an international credit card, you will be granted temporary import paperwork for your boat.
There are also requirements to sail in Mexican waters. Once you have legally entered Mexico, you will still need to get all the legal entry and departure clearances from each port. If you plan to do any fishing (or will have fishing equipment on your boat), you will need to get a fishing license before you leave. Check with the Mexican Fisheries Office.
If you are considering bringing a boat to Mexico, keep in mind that sailing along the Pacific Coast of Mexico is for experienced open-ocean sailors. If you are new to open-ocean sailing, bring along an experienced guide.
If you have boat insurance in the United States, you can usually extend the policy to Mexico for a small additional cost. You may also want to purchase Mexican liability insurance in the case you have an accident and cause damage to Mexican property.
Excerpted from the Second Edition of Moon Living Abroad in Mexico.