The OP's original statement (post #1) was that EANx was part of his AOW class, and he -- like you -- did not understand how that gave him a Nitrox cert. It doesn't, is the answer. But if he does one Nitrox dive as an adventure dive, and another concurrently with another adventure dive, (and does five Adventure dives all together, including Deep and Nav) and does the EANx bookwork and practical and tests, then he gets AOW cert and an EANx cert. Apparently at no extra cost. So it is a good deal financially, but he loses out on doing five "real" adventure dives....he just does 4 plus EANx. The alternative is to do the AOW with five real adventure dives, and do the no-dive AOW separately, and spend more money. At least, that is the most I can make of his incomplete information.