And as an example of the differences among agencies, SSI's OWD course tells students that 100 fsw is the "recommended maximum recreational depth" and 130 fsw is the max depth after the Deep Diving specialty course. Plus a recommendation, similar to PADI's, that new divers limit themselves to 60 fsw until they're comfortable and controlled enough to venture deeper.[snip]PADI's limit for OW certification is 130 feet. Divers with only an open water cert are recommended to stay above 60; AOW gets you down to 100, and the Deep specialty gets you to 130. Note that those depths are recommendations.
Im my OWD courses I introduce some rules of thumb for new-diver gas planning, one of which is "don't plan to dive deeper than the number of cubic feet of gas on your back."
-Bryan