The certification limits do not define the term "open water"
The term serves to differentiate from confined water, per PADI and RSTC standards, NOT from overhead or decompression situations. Most continuuing ed course curricula, including wreck and deep, call for open water dives, in addition to or as opposed to confined water dives.
An open water dive certification implies the ability to dive in open water, as opposed to confined water. The certification title inclusively states the upward increment in ability, rather than exclusively stating the downward limitation. An wreck diver may also be a cave diver. A certification states what one IS qualified for, not what one is not qualified for. A night diving card says one is qualified to dive at night - it doesn't say they are not qualified to dive wrecks. The cert name states the INCREMENT to be conferred above the qualifications of prerequisite levels.
H2Andy:
This is not a matter of getting a life, Andy. Someone asked an objective question, and you gave a wrong answer.
You completely and utterly misstated the meaning of the term "open water" as long established by the agencies and the industry. The definition is in black and white in the PADI standards and RSTC standards.
RSTC standards define confined water as "Any body of water that offers conditions similar to those of a swimming pool."
and distinguishes open water as being other than confined water.
The RSTC standards also allow OW certified divers in overhead environments, and only exclude divers who have not yet completed open water certification from overhead environments.
Quite simply, you gave a wrong answer, to a question you apparently are not qualified to answer, and thus potentially led a beginner to an erroneous understanding.
Perhaps I should not have suggested consulting your OW text; the answer may not be in there, but that doesn't mitigate the need to correct the faulty information you offered, and you've demonstrated before that you won't melt if I state it plainly without any syrup, so get over it. I've been corrected here, and I didn't resort to whining admonitions to "get a life."