Mexico has completed the reorganization of its marines (Infantería de Marina, or Naval Infantry.) The force has 20,000 troops, organized into;
Security forces, consisting of thirty battalions which guard ports and coastal installations. There is also one battalion that is part of the Presidential Guard brigade in the capital. The Presidential Guard battalion is an elite force, while the security battalion are more police than combat troops. But these battalions have combat training, are equipped with heavy weapons (machine-guns and such) and like the rest of the force, is pretty incorruptible.
Two Amphibious Brigades, each containing artillery and commando units, in addition to three infantry battalions. These are what the U.S. would call marines,
Special Operations Forces, consisting of battalion size Special Forces Groups, each with about 200 troops.
One paratroop battalion, another elite unit.
In the last few years, several thousand Naval Infantry have been diverted to fighting the drug cartels in northern Mexico and in port cities where the drug gangs are active. The marines are considered more disciplined and incorruptible than other military personnel, and often show up in news accounts of drug gangs being defeated in gun battles.