I just got back from two days in Key Largo where we did a total of 4 dives. Did a 2 tank charter with Conch Republic and 2 tanks with Silent World.
Conch Republic has a very friendly staff, and nice shop and great prices, especially with a SB discount. Both of our dives were very shallow (I think the deepest I got was 26 feet) because we were with a bunch of OW students. However, the sites were pretty nice, lots of life, great viz and amazing warm water (72 degrees), but everyone else was complaining about being cold, to the point where several people skipped the second dive. So, if you get cold easily keep that in mind. My biggest complaint with Conch Republic is the larger boat, which wasn't bad because there were only about 14 people on our charter, but I'd imagine it would be fairly uncomfortable if it were completely filled. The boat crew wasn't bad, they didn't seem to jump up and offer any assistance at first, but once they noticed something or you got their attention they were very helpful and friendly.
Silent World I was initially unimpressed with. The people in the dive shop were rather cold and not overly pleasant when we checked in the night before our dive. The price was good, and the boats in pretty nice condition. The boats are rather small, which is great if they aren't filled (we had 7 people with us) but if they were filled (capacity is 12 or 14 I believe) it would be a very tight, very uncomfortable fit I'd imagine as the 7 was getting cramped. Again, we were with a group of students, so again very shallow dives, one to the City of Washington and the other on S. South Ledge. Again, nice dive sites and plenty of life. Water temperatures still 72 degrees. The boat crew was very nice and helpful, and made up for the cold reception we got the night before. The boat is also easier to get on in waves than the Conch Republic boat was.
I would book again with both of these operators, especially with Conch Republic. I would, however, try to find a six-pack to go out on, because I'm a fan of smaller, more personal boats.
The seas were choppy when we went, 4 foot seas at times which led to some fairly strong surges at times and a few upset stomachs. They all said the water was a bit cooler than normal, but as of March 2-3 the temps were 72 at 20 feet.
I would also like to highly recommend Rib Daddy's Seafood and Steaks (MM102.5) for dinner. The service was amazing, the food was excellent and the prices fairly decent. Nothing too fancy, just good BBQ.
-Geoff