We are looking for the BEST dive sites on Key Largo in March

[Rae HalfTheHill]

If you are experienced divers you will likely be disappointed with Rainbow Reef. If you like cattle boats and following an inexperienced guide around, short dive times, and not lobstering then stay with RR.
If you are already booked at the Marriot and want a close shop then I would pick Horizon Divers over Rainbow Reef every time.
I recommend Conch Republic Divers just a few miles south for lobstering, experienced staff and better dive sites.

I'm curious the last time you have been out with RR? Generally the boats are only "cattle boats" on holiday weekends or perhaps spring break. Most trips that I've run in the past several months have had 15 people. Guide ratios have been right around 4-5 divers per guide.

I'll agree that each shop here caters to a different niche of diver, as well as different types of diving. If OP is desiring double dips on Spiegel, then Horizon is safe bet. For variety in dive locations, Rainbow is unmatched. Conch Republic (I believe) allows for lobstering on specific trips.

@arubabob1 - Water temps this week have been 75/76 degrees. Definitely on the upswing, but still the potential to get chilly, especially if you have full days of diving.

 

[Capt Jim Wyatt]

If you like cattle boats and following an inexperienced guide around, short dive times, and not lobstering then stay with RR.

How many times have you had the cattle boat/inexperienced guide experience at RR?

 

[Phteven]

I was just at Key Largo a couple of weeks ago and had a stellar experience with Rainbow Reef.

I'll be the first to admit I am not the most experienced diver in the world and my group are similar, so we wanted somewhere that had guides to make sure we were seeing cool stuff and having fun, but we don't need extreme hand-holding either.

In the course of 4.5 days we had a good variety of sites, and felt that RR provided an excellent end-to-end process.

Yes, RR does do timed dives instead of gas-limited dives, so if absolute maximum time under the waves is your goal, maybe they're not a good fit, and lobstering is presumably something you'll want to explore with another operator for some dives. On my future trips I'll definitely be using RR as my first-choice for operator in general even if perhaps I might do a few dives with other operators for doing specific stuff like if I decide to take up lobstering or spearfishing or whathaveyou.

 

[LI-er]

How was the marine life on the Duane?

It's one of my bucket list items for my upcoming trip to SE Florida.

 

[Phteven]

How was the marine life on the Duane?

It's one of my bucket list items for my upcoming trip to SE Florida.

It was freakin' rad, I saw a grouper that seemed to be the size of a small car inside the wreck during a swim-through

plus a big school of spadefish (I think?)

and plenty of barracuda

 

[Phteven]

Hi @arubabob1

You and your daughter are both experienced divers. You would likely appreciate some of the more advanced dives, Spiegel Grove, Duane, Bibb, Molasses Deep/Drift, French Deep/Drift. Two other favorites of mine are Snapper Ledge and the Benwood. There is a nice wall 60 degrees off the bow of Benwood that few dive, something like 45-100 feet.

Interesting thing about that wall is seeing it on a night dive. I kinda forgot it was, and sweeping my light around and having it suddenly just go off into the abyss was pretty cool.

 

[Capt Jim Wyatt]

I was just at Key Largo a couple of weeks ago and had a stellar experience with Rainbow Reef.

That is an impressive list of dive sites!!

 

[LI-er]

That is an impressive list of dive sites!!

Here's the thing about Rainbow Reef.

The not so great is that it's a huge cattleboat operation with at least a half a dozen active boats often filled with over 20 divers and it gets so busy that you actually have to book a place on the mooring line ahead of time to reserve a place for your safety stop. They they have an app for this, it's similar to booking a table at a restaurant, you specify the time you'll be there and your preferred depth, and they put a name tag on the line so you can find your spot at the end of the dive.

Despite being so freaking busy, the operation is very well run and what I really like is their detailed schedule which shows you all the dives they're going to be doing, months in advance so you can pick and choose your favorite sites. Between all their boats they cover a TON of dive sites. Most dive ops have a calendar and only a few are very specific as to where they plan to go which makes arranging a trip somewhat problematic if you have specific sites in mind, which is exactly what I'm going through right now.

 

[Capt Jim Wyatt]

The not so great is that it's a huge cattleboat operation with at least a half a dozen active boats often filled with over 20 divers

That happens during holidays, and sometimes on weekends, but not often. I rarely see it happen otherwise.

Full Disclosure: I have worked there as a captain & still do sometimes.