Abbreviations: Writing in Shorthand

A wise Undercurrent member pointed out that not everyone abbreviates SMB or DSMB, so that some readers may be unfamiliar with these abbreviations.

SMB: A surface marker buoy is deployed throughout a dive, and divers reel the line in or out as their depth changes.

DSMB: Divers deploy a delayed surface marker buoy when about to surface or at a safety stop to signal their location to the boat. Its line is usually deployed from a spool or unwound from a bag. Self-sealing DSMBs do not collapse if they fail to stay upright on the surface. They also alert other boats to divers in the water. You can't always hear approaching boats when you are diving.

- John Bantin