Wiktionary
n. A person responsible for a group of underwater divers
Wikipedia
A Divemaster (DM) is a diving qualification used throughout most of the world in recreational scuba diving for a diver who has overall responsibility for a group of divers. As well as being a generic term, Divemaster also refers to the first professional rating of many training agencies, such as PADI, SSI, SDI, NASE, except NAUI, which rates a NAUI Divemaster just under an Instructor but above an Assistant Instructor.
The BSAC recognizes several agencies' Divemaster certificates as equivalent to BSAC Dive Leader, but not to BSAC Advanced Diver. The converse may not be true.
The certification is a pre-requisite for becoming an instructor in recreational diving with most agencies except NAUI, where it is an optional step to Instructor, because of the different position of the NAUI Divemaster in the NAUI hierarchy.
The Divemaster level equals to the international Standard ISO 24801-3.
Usage examples of "divemaster".
Maui, preferring to work as a divemaster with an established concern instead of opening his own business.
To them, divemasters like him were pampered, underskilled wimps who liked clear water and clean sand.
The Mikado III, captained by Mike Amell, an experienced divemaster, was chartered.
They waved to the researchers at the fuel dock, nodded to the haglets at the charter booths, shakaed the divemasters and the captains, and schlepped science stuff down the dock to start their day.