If by "long hose", this is a long hose + bungied second, I'd not be surprised if an Instructor said "no" to someone using it as a DM or to a student at an Open Water level.
A DM (the original topic of this thread), at least in PADI, is supposed to be able to work with students on skills after the Instructor has demonstrated them. Also, particularly in air sharing, a DM often does the demo with the Instructor, since it's inherently a two-person activity. If you want to be a professional you follow the standards of the organization you are seeking to become a pro in, including the skills to be demonstrated -- the four-letter dive orgs are not DIR, and if you wish to be a pro in one of them, you follow their standards (including equipment configurations used -- standard primary and octo is what we learn on).
Likewise, I can't see someone acting as a DM "out in the wild" on charters (unless they're explicitly DIR charters) using a long hose configuration. You ought to be running as vanilla a recreational configuration as humanly possible, so that when a client has a whoops there's no issue with them grabbing a reg -- don't tell me you do S drills with all the clients on boats, I ain't gonna buy it.
Likewise, if it's a student in an OW class it is entirely appropriate for the Instructor to say "nope". Folks need to follow the fitouts used by the PADIs and others of the world. It's not the Instructor's job in an OW class to be teaching alternate configurations -- feel free to take DIR-F afterwards, but you do not dictate what you will be taught as an OW student.
I know PADI Instructors who are tech divers, normally off with their doubles and stage bottles. When it's time to work OW, however, they drop back to a standard configuration. What is appropriate or not does depend on what is being taught.
A DM (the original topic of this thread), at least in PADI, is supposed to be able to work with students on skills after the Instructor has demonstrated them. Also, particularly in air sharing, a DM often does the demo with the Instructor, since it's inherently a two-person activity. If you want to be a professional you follow the standards of the organization you are seeking to become a pro in, including the skills to be demonstrated -- the four-letter dive orgs are not DIR, and if you wish to be a pro in one of them, you follow their standards (including equipment configurations used -- standard primary and octo is what we learn on).
Likewise, I can't see someone acting as a DM "out in the wild" on charters (unless they're explicitly DIR charters) using a long hose configuration. You ought to be running as vanilla a recreational configuration as humanly possible, so that when a client has a whoops there's no issue with them grabbing a reg -- don't tell me you do S drills with all the clients on boats, I ain't gonna buy it.
Likewise, if it's a student in an OW class it is entirely appropriate for the Instructor to say "nope". Folks need to follow the fitouts used by the PADIs and others of the world. It's not the Instructor's job in an OW class to be teaching alternate configurations -- feel free to take DIR-F afterwards, but you do not dictate what you will be taught as an OW student.
I know PADI Instructors who are tech divers, normally off with their doubles and stage bottles. When it's time to work OW, however, they drop back to a standard configuration. What is appropriate or not does depend on what is being taught.