DunkelBierJay

You need to make sure the pool work happens on board during your cruise. PADI is the agency that is on RC ships, and you will need to complete your online coursework beforehand. Some dive shops may still offer in person class room training and pool work.
Here are the ships that offer it:
https://www.royalcaribbean.com/faq/questions/what-ships-offer-padi-scuba-certification
Here is a list of FAQs:
https://www.royalcaribbean.com/faq/topics/padi-scuba-courses-and-excursions
Personally, if I was interested in it, I would get certified through a dive shop that is local to you and get to your cruise with your C-card in hand so you don't have to worry about it while on vacation. That way, you can book scuba through an excursion or through a shop directly at a port visit. I've done both and prefer to book dives through a third party if getting to their dock is easy like it is in Cozumel. It's also a good experience to do it through Royal...slightly more expensive in my experience, but they get you there and back with no issues.
 

^^^ This ^^^  It is much cheaper and easier to do it locally.  Save the trip for enjoying fun diving experiences where you can enjoy the underwater sights, not learning and constantly having to "think" and check your instruments because you are new to them.

I am a PADI Open Water Scuba Diver Instructor, your best bet would be getting ceritifed before your cruise, and see if there are any diving shore excursions on trip, if not see if there are any PADI Dive centers at your ports of call

My opinion, having been with someone who did it on a trip is... DON'T DO IT.  It will monopolize your trip.  It takes valuable time away from the vacation with your family.  It is much better to do it another time... either before of after your trip.

You need to make sure the pool work happens on board during your cruise. PADI is the agency that is on RC ships, and you will need to complete your online coursework beforehand. Some dive shops may still offer in person class room training and pool work.
Here are the ships that offer it:
https://www.royalcaribbean.com/faq/questions/what-ships-offer-padi-scuba-certification
Here is a list of FAQs:
https://www.royalcaribbean.com/faq/topics/padi-scuba-courses-and-excursions
Personally, if I was interested in it, I would get certified through a dive shop that is local to you and get to your cruise with your C-card in hand so you don't have to worry about it while on vacation. That way, you can book scuba through an excursion or through a shop directly at a port visit. I've done both and prefer to book dives through a third party if getting to their dock is easy like it is in Cozumel. It's also a good experience to do it through Royal...slightly more expensive in my experience, but they get you there and back with no issues.
 

You need to make sure the pool work happens on board during your cruise. PADI is the agency that is on RC ships, and you will need to complete your online coursework beforehand. Some dive shops may still offer in person class room training and pool work.
Here are the ships that offer it:
https://www.royalcaribbean.com/faq/questions/what-ships-offer-padi-scuba-certification
Here is a list of FAQs:
https://www.royalcaribbean.com/faq/topics/padi-scuba-courses-and-excursions
Personally, if I was interested in it, I would get certified through a dive shop that is local to you and get to your cruise with your C-card in hand so you don't have to worry about it while on vacation. That way, you can book scuba through an excursion or through a shop directly at a port visit. I've done both and prefer to book dives through a third party if getting to their dock is easy like it is in Cozumel. It's also a good experience to do it through Royal...slightly more expensive in my experience, but they get you there and back with no issues.
 

I'd suggest making two threads, one for each sailing.
I'll be on the April 15 sailing!

I recently stayed at the Embassy Suites which is right on the free trolley line which goes right to the port, and it was perfect.

Back to Back -- Hitting Cozumel twice and Costa Maya once with scuba at each port stop, maybe a trip to Hemingways on the first or second and maybe Nachi on the second in Coz, and Jaime's Blue Reef in Costa Maya.
Cruise 1 -- April 15
Cruise 2 -- April 20

If the price is right…I would pay the extra to make it refundable.  I do that quite often.  That way you can cancel and rebook a different date…ship…destination.  And you can always change the refundable to non-refundable once you are absolutely sure of your cruising plans.

Kinda freaked out when my phone went off, telling me I have 30 minutes to report for a safety brief.
....
Except that my cruise isn't until May 14. 🙄

Congrats to our friend @CHRIS WONG on being featured!
 

Presently sailing on Enchantment and just happened to look at Message Board and learned Catholic Mass was to be celebrated in the conference room. About 120 passengers showed up in an unprepared overcrowded room . We had to set up the chairs and accommodated everyone. It was a beautiful service conducted by two Archdiocese of Baltimore priests who we have socialized with since. We then had a second Sunday mass in the Spotlight Lounge that was attended by about two hundred passengers. The ship would not put a posting in the Cruise Compass saying it was against company policy so the message board and word of mouth was all that was used to announce the event. Curiously, the ship did post in the cruise compass an announcement for Jewish Sabbath Observance-self guided. It also posted for LGBT get togethers daily.  We are Pinnacles and this is the first time in about 30 cruises that we have had Catholic Mass on board. Apparently, Royal Caribbean does not foster having priests on board to say Mass and we saw this first hand. What a mistake!

@cactusgirlI reactivated my certification in October of 2021 through a local dive shop. The open water check out was in a quarry and it was nice to have that taken care of when I dove on Coco Cay on my Indy cruise (that dive was not all that great, btw)...see my signature for descriptions of a couple of dives with Royal on Roatan and with a shop in Costa Maya -- I have dives booked with Royal and with independent shops in Coz and Costa Maya on my up coming back to back....while I haven't done the pool training on a ship, I think that it takes a huge amount of time and energy while in vacation, and unless you really want to do it that way, I recommend getting your C-card at a shop that is local to you, and arrange your check out dives with them or with a shop at a port that they may be affiliated with. I don't know of a shop that doesn't do trips to the Caribbean and has good contacts in Cozumel and Grand Cayman...that's just my $0.02. I say all this because I've experienced poor response times from Royal's scuba team myself.

Yes, we booked the full island tour and the facility with the sloths and monkeys, and it was a fantastic experience. Highly recommend.

There are about 100 dive shops in Coz. I've used Dive w/Martin back in 2019 before covid. They were good. Going back to Coz in February and diving with Blue Reef Divers this time but only because it is the in house dive shop for the all inclusive resort my family is going to the day we are there.
I had originally booked  with Sand Dollar Sports which is what RCI uses for their ship excursions. The ship dive was sold out.  SDS is a 3 or 4 block walk from the pier.
Dive paradise was also highly recommended.

We used Dive Paradise, but it was about 10 years ago. They had rental gear, but we brought our own since we drove to the embarkation port. 
https://diveparadise.com/

Wellllll, THAT subject was clickbaitey

We always use Cozumel H2O when we visit.  They offer scuba and/or snorkel depending on your desired experience.  It's a short taxi ride from the port.
 http://www.cozumelh2o.com/
 

This really can't be quantified as the best pours will depend on you and your tipping habits. 

If I was flying or taking the train from Madrid or Paris...maybe...If I was flying from anywhere else...if it's the US, I would plan on two days before and enjoy a little more tapas

Wellllll, THAT subject was clickbaitey

Rarely, when I go to an all inclusive or do an excursion do I develop an emotional attachment to a place and to a staff on shore like I do with my stateroom attendant and MDR waiters, but Jaime's at the Blue Reef did that for my wife and me.
The staff and service is friendly, welcoming and impeccable. Martin, Digby and Rodrigo are at risk for becoming famous for their service and wonderful approach. The food is outstanding, the margaritas are really tasty (try the tamarind), and the atmosphere is festive and restful at the same time. The beach is fairly small, but the water is warm and shallow in close proximity to the huge reef off shore, and there is a rooftop pool with an amazing, albeit windy view when we were there. When going up the steps, you notice there are no room numbers. The rooms are designated by fish species names.
I really like the proximity to other amenities along the beach, and Pepe's Dive Shop which is attached is absolutely fantastic. It was staffed by Pepe (not the owner), Siri (divemaster), and Cata who I believe is also a divemaster/instructor.
The reviews on TripAdvisor are legit as well. My only hesitation is that the word will get out, and it will become increasingly difficult to get a reservation for next time. And, yes, I am going back asap.
Since the location is in the middle of the beach in Mahahual, there are vendors who come up trying to sell stuff, but they aren't pushy. One is in a pic below and is dressed as a mime.


 

 

 


 

That's not worth the risk of missing the flight even with self-assist. Technically, if the ship makes it alongside in time, clears, you self-assist and are first in line, there is a chance, if you can get an uber/lyft quickly. There are too many variable though, and if I did that, I would be as stressed as I could be. I don't think I would do that even if the sailing was out of Port Everglades with the airport ten minutes away. Port Canaveral? Everything has to work perfectly. What if you looked at Jacksonville or Melbourne? I've flown into both before, because I hate Orlando airport...maybe there's a later flight out of one of those airports.

When there is an event like this it is interesting to observe human behaviour.  People who are otherwise logical and sane people begin to lose their ability to reason.   
Crew are making announcements but they are ignored.   People see other people ignoring the announcements and they begin to follow. It's grows into a mass of people congregating in an area despite crew best efforts to avoid that.  
Our internet continued to work and so did our drink packages but having to haul luggage around was a drag.  
It becomes a "get me outta here" thing even though there is no threat or risk on the ship.  Some people handle the stress well but many lose it.  You can feel a tension in the air.  When they finally start letting people off it's a free-for-all.  Total mob mentality, anything goes, run over grandma's feet with your luggage.