Is there excellent snorkeling anywhere in Florida?
Thanks!

I don't know what your definition of "excellent" is, but this place is pretty good:

www.pennekamppark.com

Florida is a big state with some 2,300 miles of tidal coastline and along that coastline there are some decent areas to snorkel and you'll find lots of places in the Florida Keys, many areas accessible only by boat. If you do a google search for "Florida Snorkeling" you'll find plenty of links that will tell you where to find "the best".

Pennekamp.

That's the answer!

You might want to look at Lauderdale-By-The-Sea which on the Atlantic coast. They have a snorkel trail. Here's a description:

"Known as the “Diving Capital of South Florida,” Lauderdale-by-the-Sea is famous for the coral reef that is only 100 yards away from the beach, attracting a flood of tourists every year. There is also a snorkel trail along an artificial reef that is 12- to 14-feet deep. The city is an ideal vacation spot, filled with motels, hotels, restaurants and a fishing pier. The city is 5 miles from four museums. It is also just up the beach from Hugh Taylor Birch State Park and a short drive from John U. Lloyd Beach State Recreation Area."

http://www.lauderdalebythesea-fl.gov/snorkeltrail.htm

You can request a free visitors guide:
http://www.lbts.com/request.html

That link may not be good any more - you can try this one:

http://www.lauderdalebythesea-fl.gov/muni/snorkel.htm

I have never found the snorkeling at Pennekamp, or anywhere in Florida to be "excellent". Water too murky/turbid and not much marine life as compared to truly excellent places like Fiji.

We like snorkeling at Pennekamp as well as off Key West. The best suggestion is to watch the tides. Try to go at the low tide for the day, visibility is clearer and the chop is milder.

Also in the Keys, Looe Key is great for snorkeling. It is actually an area of underwater reefs off the lower middle keys which are accessed by boat. You can go on tour trips out there.

I've not done this - yet...
...but the next time I am in the area I want to go to the Dry Tortugas to go snorkeling

http://www.yankeefreedom.com/key-west-snorkeling.htm

Looe Key Dive Shop has a snorkel trip with three stops . It was beautiful.