Might ask over in the Southwest Sand Sharks forum, we go there all the time. Are you in Phoenix or Tucson? If so, other options would be
Scuba Specialties,
Ocean Planet or the
Dive Shop in Tucson. Most run regular trips down, El Mar - and sometimes OP - have a bus. Last October we went down on our own and both SS and OP were also there. So some of the boats were booked.
A good place to stay is
Marina Terra since it's right on the marina that all the boats leave from. And imho it's one of the nicer places in town. They also have a beach club a short walk away for non-divers. Ask at the desk and they'll take you over there in their golfcart. An even better deal is to rent a condo from
Ocean View Realty at the resort.
Sharing you can rent a condo cheaper than the hotel rates. The condos are part of the resort so you share all the amenities. They're just a short walk(100 yds.) off to one side. And the rental office is 50' from the hotel lobby. I rented condo A117 for $150/nt. Full kitchen, two patios with marina views, full A/C, everything except a phone. The second bedroom is set up for kids though. There's two food stores within walking distance, one's nearer to the condos than the resort. And at least 5 restaurants within walking distance also. It's a cliche' but
don't drink the water...
My friends rented a 4BR suite in the hotel from Ocean View for much less than the hotel would've charged.
Two other dive operators to consider are
Surface Time or
Gary's Surface Time's office is located 100 yds. from Marina Terra, Gary's is on the main road in town. So if you dive with Gary's, stop and pay first then drive to Marina Terra.
All the boats leave from the marina in front of Marina Terra. Gary has a couple of fast boats and several slow boats - old concrete-hull tourist boats. Try to get on the fast one if you're going out to Seal Island - where most of the good diving is. On a slow boat it can be a long ride out. More advanced stuff is to the south around the point, but the most fun is to dive the coves when you see the seals on the rocks, after you hit the water, they'll come over and play - or at least check you out.
They did indicate that unfortunatley the stinging nettle jellyfish can be quite plentiful in early spring anyone encountered this?
We dove there last October in some rough conditions. So there were pieces of jellyfish in the water at one site. They sting when they hit you but it's not a divestopper. At least for me. And I dive in a swimsuit/t-shirt. My friends in skins didn't mention it.
btw, instead of a 10hr. drive from Phoenix, you can fly there on US Airways...A cab from Guaymas is $20 one way but rent a car or you'll be stuck at Marina Terra, it's pretty far from town - and on a bus route.