Marine (military)
The Mexican Naval Infantry (Spanish: Infantería de Marina) of the Mexican Navy consists of 20,000 marines spread in a brigade of three battalions, plus a battalion attached to the Presidential Guard Brigade, three regional battalions with headquarters in Mexico City, Acapulco and Veracruz, and thirty-five independent companies (mainly In Celaya) and detachments distributed among ports, bases and zonal headquarters. The marines are responsible for port security, protection of the ten-kilometer coastal fringe, and patrolling major waterways. The marines have light arms, heavy weapons and armored amphibious vehicles. The Navy has ceded most of its riverine responsibilities to the Army, and has reduced the size of the marine force, putting them back aboard ships where they play a vital role in drug interdiction and boarding of suspect vessels in territorial waters.