My friend Kym is addicted to scuba. She and her husband plan 5 day Zihua trips and she will work in three or four dives. She was nice enough to invite our friend Victor and myself to try scuba diving for the first time, and I documented the process for anyone else thinking of giving it a shot. For beginner divers, the Discover Scuba Dive is what you will be doing. This is what Victor and I did.
Kym, Ali, and me 
Ali and Alan
There are at least four different Dive shops in Zihua. I’m not sure if they are all connected in some way, or totally separate. All four can be found on facebook and have websites. Any of these shops can get you PADI certified, which then will allow you to do the more fun dives. Kym says Zihua is a great place to get PADI certified. The costs are about the same no matter where you go, but the comfortable water and good visibility make it much easier to pass the course over many other places.
Carlo Scuba (carloscuba.com): They have a Discover Dive that includes one dive for $90USD. A 2 day PADI course costs $295. A one tank certified dive trip is $65, a two tank trip is $90, and a night dive is $75. They are located on Playa Las Gatas.
Adventure Divers (adventuredivers.mx): They have a Discover Dive that includes one dive for $90USD. A two tank certified dive trip is $90. They also offer PADI certification, but no other pricing is listed online. They are located in Centro.
Dive Zihuatanejo (divezihuatanejo.com): Their Discovery Dive is $100, but their website doesn’t clarify if it’s a one or two dive trip. The website has lots of price options for trips, and all seem to fall in the same price range as the others. They are located in Centro.
Zihuatanejo Dive Center (scubazihuatanejo.com): This is who we went with. They are located in Centro on the other side of the pier.
We paid $110 for a Discover Dive. Ali, my wife, had to pay $30 to come along for the ride. She brought her own snorkel gear and snorkeled off the boat at each stop. Kym and her husband, Alan, also came, snorkeled and swam, while Victor and I did our thing.
We all met at the Dive Center at 2:30pm. We first had to fill out some simple paperwork, essentially releasing the Dive Center from all liability. We were able to pay in USD, pesos, or by credit card. At 3pm we hopped in the boat and took off to our first stop. At Playa Contramar we were taught the basic hand signals, learned about the scuba equipment and some important underwater tips. For example: What do you do when you lose your regulator mouthpiece? This came in handy when I accidentally knocked the regulator out of my mouth at 30 feet deep.
Feeling good! 
I’m ready to go. I think Victor was praying.
We had a good captain, Toto, and our divemaster, Sarah, was very patient with us.
After our initial lessons we rode to Manzanillo for our first dive. Over about 30 minutes we explored and looked for different underwater animals. We followed that up with another dive at a nearby site for another half hour. We reached a maximum depth of 40 feet and all was good. I also brought along my handheld electric sea scooter and everyone got a kick out of speeding in and across the water on it.
We arrived back at the Dive Center at 6:30pm, and I am not sure I have ever been more exhausted. I still haven’t decided if I’ll go for the PADI certification and more dives. But Kym and her husband just purchased a condo here, so I have a feeling the peer pressure may eventually get to me.