When we say Carmel and Monterey sides, we're talking only about a 10-15 minute drive between the two, if the traffic's heavy.
And the three-two-five/moby ling cove/waterfall beach area is REALLY rugged and has gotten progressively worse over the last couple of years, and the stairs have been completely washed out and replaced with huge ruts at least 3 feet deep and rusty steel rebar sticking up. Mostly sandstone type geology with hard, sharp granite right near the water. At least the very heavy surf has cleaned the granite of any sand or talus and the footing there is secure. Most of us know the sites by their mile markers on the side of Highway 1, as in MM 66 and MM 67, in Garrapata State Park. It's a beautiful area, both on the surface and underwater, but access to the water is difficult, to say the least - think of hiking 1/2 mile or more in full gear (you suit up at your car, parked on Highway 1 near the respective marker) through poison oak lined, loosely marked/overgrown trails, then carefully crawl down through the washed out sandstone and onto the granite. Oh, and don't forget to watch the wavesets. And don't even go near the water if the swells are over about 5 feet. And when you're finished diving, you still have to get back out of the water, back up the cliff and hike back to your car. This is not, by any stretch of the imagination, like any other shore dive most people have ever done. Oh, I'd be willing to rappel or belay down, but the truth is that there's nothing around to hold or grab onto, much less anchor and tie off to, so you're stuck scrambling down loose cliffs and washed out trails. And you'll need to bring a change of shoes to hike down and back as your booties would probably be shredded when you're done if you used them. That said, I'm diving this area on Saturday-from a boat.
Let us know the day(s) you'll be here so we can make reservations at Point Lobos and we'll dive with ya! Point Lobos' entry is kind of like Casino Point (substitute a boat ramp for the stairs though), then there's a drop-off, then you go diving. For the really cool spots you'll need a boat or kayak though, or a fairly long surface swim. I'd actually put Point Lobos ahead of Monastery or Butterfly House, but you need reservations.
Monterey Bay Dive Center, Glenn's Aquarius, and Bamboo Reef are all near the Breakwater, and they'll rent Nitrox, IIRC. You'd pick up your tanks there, then drive to Carmel as there aren't any dive shops in Carmel.