Diving around Sacramento?
Lake Tahoe......big, cold swimming pool. 2 hours from Sac. Sand and big rocks.
Mountain Lakes. Yawn.....unless you're into gold prospecting. Gives it a purpose. 2 or more hours from Sac.
Monterey Bay. Green water. Interactive mammals. 7mm wetsuitable year-round. 3 hours away. Colors come alive under the glare of a flashlight.
North Coast (Gerstle Cove, Ocean Cove). Just a degree or three colder than Monterey. Less crowded. 3 hours away.
Point Lobos. Beautiful. Crowded on weekends. 3 hours away.
Big Sur. Advanced. Equally beautiful. Take a boat from Monterey.
Six hours south by dive truck you have boats to the northern and southern Channel Islands, including Catalina. Water temps are usually 5-15 degrees warmer than the north state year round. Similar underwater topography to the north state. Watch out for the "aggressive Garibaldi" (inside joke).
No real direct flights to anywhere, but once you connect out of San Francisco, Oakland, or San Jose, Baja and Vancouver are only a 3, 3.5 hour flight; Hawaii, Cancun, and Cozumel are all five hours.
Within an hour or three of Sacramento you'll find great skiing; fantastic sightseeing; a hypnotic coastline; unbelievable backpacking; the laid back wine country; incredible motorcycling (coastal range and mountains); Yosemite, Lake Tahoe, Reno, and San Francisco. Vegas is a short flight away. If you're into golfing, there are over 50 golf courses around Sacramento. And finally, let's not forget the meth labs of Modesto.