SEa Air and Land teams (SEAL - get it? ha ha).
SEALs are the Special Operations unit of the US Navy, so most bat for the other team. Their main roles revolve around doing jobs the USMC should really be doing, including direct action, counter terrorism, underwater demolition and beach reconnaissance.
SEALs go through one of the hardest selections in the US military. That's not saying much but it's still got a fairly low pass rate - about 1/4. Within the "Teams" DEVGRU (formerly SEAL team 6) are the CT experts and the elite within the elite and often cross train with the SBS.
The selection is known as BUDs (Basic Underwater Demolition/SEAL training) - a name derived from the old US navy UDTs (Underwater Demolitions Teams) to which the SEALs in Vietnam were recruited, before having their job usurped from them. Halfway through there's 'Hell Week' in which the 'tadpoles' go through a week-long beasting (think Ex. First Night at CIC, but with more sleep).
After this they spend the rest of their career wandering around a beach shouting "Ho-Yar" at people, then occasionally going for a run.
Royal Thai Navy Sea, Air and Land (SEALs) (Thai: หน่วยซีล or หน่วยทำลายใต้น้ำจู่โจม) is a 144-man special operations force within the Military of Thailand. The unit was set up in 1956 with the assistance of the U.S. Government and has trained with United States Navy SEALs. A small element within the Royal Thai Navy's SEAL Teams has been trained to conduct Maritime Counter-Terrorism missions. The Royal Thai Navy SEALs are nails compared to the yank ones.