I live in Loreto (2 years now, full-time), and have only dived in Cabo Pulmo a couple of times. To be honest, both of my Cabo Pulmo experiences were ... in my opinion ... disappointing. I'm sure there's great diving to be had there, but it wasn't my experience. Take that for what it's worth ... just two data points (four dives) that didn't meet my expectations. I know there are some great dive sites to be had there, but they limit the number of boats to those sites on a weekly basis, and if you're not lucky enough to be on one of those limited boats, the sites they will take you to are pretty ordinary.
Loreto has some great diving, some good diving, and some average diving ... depends on who you go out with, and also on weather/wind conditions ... which this time of year can dictate where they can take you. For diving, you have three options ... Land and Sea Tours, which offers multiple services that include diving ... Dolphin Dive, which is a dedicated (and pretty well-run) dive operation ... and Blue Nation, which is my preference because I like their attention to details, customer service, and sustainable (environmental) diving practices. So you know who I would recommend if you're coming to town.
Most of the diving is out on the islands ... specifically, the three closest islands ... Coronado, Carmen, and Danzante. They all have their unique attractions. Coronado is the closest, is an ancient and dormant volcano, and is home to the local sea lion rookery. Lately the sea lions have been pretty active and interactive, and if you haven't experienced diving with sea lions, this may be something of interest. The site also has a very nice reef if the currents let you get out to the point ... sometimes it's just too strong to get out there. If you get stuck inside, look at the small stuff ... jawfish are a particular attraction, as well as some other smaller stuff. If you go with Blue Nation, Yago is especially good at finding interesting things to look at, and will give you a pretty good education about what you'll be seeing during the dive briefing. Carmen is the largest island, and has many significantly good dive sites. Some of my favorites are some pinnacle sites (Palo Blanco and Los Picachos), and one deep site called The Abyss that always has cool stuff to see (eagle rays, etc). There are literally dozens of sites on Carmen, due to its size, and weather and wind will dictate which ones you will be able to visit. Danzante is my favorite island overall, and has several really nice reef sites, a wall dive, and one of the nicest beaches for surface interval. During the Covid quarantine (still ongoing, to some extent) these may be closed off ... it's tough to tell until you get there what the park is going to do. But overall the diving here is really nice. There are other dive sites not attached to an island ... some seamounts, and a couple really nice reefs north of Coronado on the mainland. Again, weather and wind will dictate where they can take you this time of year.
Besides diving, Loreto offers some things that Cabo Pulmo generally does not ... mountain hikes (the canyons of the Gigantes are spectacular) and kayaking. Sightseeing in the mountains ... a trip to nearby San Javier is a beautiful drive to a tiny local village. Cabo Pulmo, on the other hand, is fairly isolated by several miles of dirt road ... it's relatively close to Cabo San Lucas, if you're into night life, but getting in and out can be a significant hassle, and impossible if you don't have a car.
If you have any specific questions about Loreto, I can answer those for you ... suggest PM, as I have only recently started coming to this site on a regular basis, and might take a few days to notice anything you post here. It's a pretty magical place ... even during a pandemic.
... Bob (Grateful Diver)
