Sorry, I disagree,
@SaltyCracker. Even a quarry would be more realistic than Blue Grotto, which doesn’t get more than about 40 ft deep. While it has been said that a certification is like a learners permit for driving, it has also been said one becomes certified to dive in conditions similar to those they were certified in. Most quarries, let alone the ocean, are a lot more challenging than Blue Grotto. I don’t think Blue Grotto really would put the skills one learned in confined water to the test. Wouldn’t it be more realistic on the OW cert dives to descend where you can’t see the bottom 40 ft down in gin-clear water? Oh well, I’ve stated my opinion. Best of luck with whatever you decide.