HS-East (JAX)
HS-West 4 San Diego squadrons and HS-14 in Japan
HS squadrons fly the SH-60F and HH-60H. HS Squadrons deploy off of carriers and missions include Anti Surface Warfare, Anti Submarine Warfare, Naval Special Warfare Support (flying SEALS), and Combat Search and Rescue (CSAR) (going behind enemy lines with guns to pluck out a jet guy who had to punch out). There are only 4 HS billets each month, and is the hardest slot to get.
HC-San Diego (Sierra)
HC-Guam (Sierra)
HC-Norfolk(Sierra)
HC-Norfolk (H-3's, and soon to be Sierras)
Most HC squadrons have finished the transition to the Sierra, and the rest will be done soon. The HC mission is primarily vertrep, but they will be picking up some CSAR and NSW missions when they figure out how to put more gas on the bird. It does not have the legs for that mission right now. There are only 4 HC squadrons and they have the newest birds, so it is pretty tough to get.
HSL-Jax
HSL-San Diego
HSL-Japan
HSL are the LAMPS bird and fly the oldest 60's in the Navy, the Bravo model. Their primary mission is Anti-Sub warfare. HSL squadrons deploy in small detachments on tin cans. HSL is the easiest billet to get since there are more HSL squadrons than all other squdrons combined. I have never heard of someone who wanted to go HSL and not get it. If you know that you want to go to Japan, then HSL-51 will be happy to have you.
HM-Norfolk
HM-Corpus Christi
HM-Italy is still on the sheet but is no longer an option.
HM squadrons fly the MH-53 and they usually select one or two guys a month for these squadrons. Their missions are heavy lifting anti-mine warfare.