A DSMB or Delayed Surface Marker Buoy works the same as a SMB but it is inflated and deployed from underwater. It is composed of a surface marker buoy secured by a line on a spool or by a WDS. DSMB allow a diver to be located and spotted from the surface while still being at desired depth. It helps in preventing and avoiding accidents with boats and is considered mandatory in many places.
EAN or Enriched Air Nitrox is a mixture of gases for which content is the same as air but at different ratios. It has higher concentration of oxygen than the 20.8% found in regular air. EAN is used to reduce nitrogen exposition and saturation into the body. It gives longer bottom times at given depths than regular air.
ICD or Isobaric Counterdiffusion is a term used to describe when an inert gas is diffusing in the tissues while another inert gas is diffusing out of the tissues. It is not a desirable effect as it leads to increased risk of gas bubbles formation in fast tissues.
SPG or Submersible Pressure Gauge is a gauge that translate the pressure from the tank to a unit that has measurable properties. Similar to the fuel gauge of a car. They can either be in PSI for imperial system or bar for metric system. They are the same as their regular non-submersible counterpart but sealed to block water from getting into the mechanism preventing corrosion.
END or Equivalent Narcotic Depth is used to express the relative narcotic effect of nitrogen at given depths. Also called rapture of the deep, it impairs divers when they get exposed to a certain pressure. It is different for every diver at different times. The END compares a mixed gas other than air such as nitrox or trimix to what the narcotic effect would if the dive was conducted on air.
A SMB or Surface Marker Buoy is a safety signaling device in the form of an inflatable tube of fabric brightly colored. SMBs are used at the surface to be easily visible and spotted from far away. Some can also be deployed from underwater and are called DSMB.
A Safety Stop or SS is a stop or pause that divers do at the end of a recreational dive before surfacing. They are not required in the case of an emergency but are very good practices to help prevent the onset of decompression sicknesses. They are done at 5 meters for a period of 3 minutes.
A LDS is a store, shop or dive center that provides products and services related to diving. It can be diving logistics and diving trips, equipment maintenance, rental or sales or education and certification.
The LPI or Low Pressure Inflator allows the BC or BCD to be inflated or deflated. The LPI is fed by its own hose connected to a low pressure port of a regulator first stage. There are only two buttons, one for inflation and the other for deflation.