........however many are, IMHO, worthless.
Drysuit is necessary training, although there's not enough material there to make an entire course. It should be included with the purchase of the suit.
Night diving - covered adequately in any decent advanced class there's no need for a night diving specialty.
Peak Performancy Buoyancy - teach it properly in the OW class.
Mulitlevel Diver - cover it in advanced.
Deep Diver - to not exceed 130 ft? Give me a break, this is another portion of the advanced class. If they were really talking about deep diving, I'd agree with it being a legitimate class.
Equipment Specialist - doesn't cover anything that shouldn't have been covered in OW.
Underwater Navigator - should be covered in OW & expanded in advanced.
Drift Diver - a 15 minute lecture that should be included in OW.
Altitude Diver - depending on the course location, this should be covered in either OW or advanced.
Boat Diver - this one is ridiculous. If you can't dive from a boat, you should have ANY c-card.
That's 10 different specialties that I believe have no reason to exist as separate specialties. I believe 10 qualifies as "many."
There are some specialties that require enough special training that they require their own class. Photography, Search & Recovery, Rescue, Wreck, Cavern, Ice, Cave & Nitrox immediately come to mind. I'm sure there are others.
I'm not "anti any other training agency other than YMCA." I AM pro YMCA, but there are other excellent agencies as well. CMAS, NAUI, BSAC & LA County immediately come to mind. BTW, YMCA is far from perfect. I'm not terribly familiar with many of the other agencies, but am interested in seeing standards from any of them.
Walter