Guatemala is a country in Central America. Here's the map. It is the country with the largest population in Central America.  It also has a Pacific coastline to the southwest, and a tiny piece of Caribbean coastline to the east.

Diving information is sparse, to say the least, but popular dive sites are Cabo Tres Puntas, Amatique Bay, Cayos de Belice, Cayo Limon, Lake Atitlan and Pacifico [source: 2007 Diving Almanac & Year Book]

• Lake Atitlan - a volcanic-formed lake 1500 mtrs above sea level.  Created by a huge prehistoric explosion, you can see massive volcanic rock formations, a fault line where you can plunge your hands into hot volcanic mud, a vertical swim-thru, sunken trees, and an abundance of fish, crabs and plant life.  Water temperature is around 20°C /70°F and visibility varies between 4-14m /12-45ft.  However, If you want to dive here, you need to spend the night of your dive at the same altitude as the lake. PADI now recommends 18 hours before diving at altitude to avoid decompression sickness.
  
  

• NEVER EVER take photos of children without permission. Some Guatemalans are extremely paranoid about this and will assume you're a kidnapper (even if children aren't theirs).  [Source: Wikitravel]
• Dengue Fever is endemic to Latin America and the Caribbean and can occur throughout the year.  Reported cases increased in 2007, especially in the common border areas shared with El Salvador and Honduras.
• Malaria is prevalent in the low-lying areas outside Guatemala City.  Seek advice before you go.
• BE AWARE: Lariam (mefloquine) is an anti-malarial drug used in regions of the world where chloroquine resistant falciparum malaria is prevalent. e.g. East Africa, South East Asia.  Possible side effects of lariam such as dizziness, blurred vision and a disturbed sense of balance are common and could cause problems for divers.  These effects can often imitate or even worsen the symptoms of DCI. There could also be confusion between the side effects of lariam and the symptoms of DCI or nitrogen narcosis resulting in a misleading diagnosis.
• Pacific coastal areas are very hot during March and April.