ok, we have limited time and budget for the keys and have narrowed it down to three snorkel areas ... any thought on where we'd be able to see the most marine life:
1.john pnnecamp state park snorkel tours
2.looe key marine sanctuary (w/ bahia honda snorkel tours)
3.reef off of key west (w. sandbar area)

thank you in advance for any recommendations

If you're talking about the living reef off Key West, it's a fairly long boat trip away and there's no sandbar. If you opt to snorkel there, however, I highly recommend Floridays, a sailing sloop that docks at the Hyatt.

thanks for the advice - i checked out floridays and they are even nice enough to give us a discount to $39 (we have our own equiptment) - but it's still too $$$ when there are similar outfits charging $25 (bahia honda tours offered $20 to the marine sanctuary) - at this point, i'm just trying to figure out if we should go to looe key or to the reefs off of key west?

I have not been to the other two - but we had a great trip to the Looe Key Marine Sanctuary last September. We saw barracuda, nurse sharks, lobsters etc. It was excellent - we were unable to dive because we were both congested, but being limited to snorkelling was not the disadvantage that we expected. We used the dive boat at Little Palm Island, so I cannot speak for Bahia Honda Snorkel Tours, but I would definately recommend Looe Key.

Hope this helps.

You get what you pay for. As a general rule, the cheaper the price the larger the group and the fewer the fish or sea life you're likely to encounter. Check with the charter company for group size. Groups of 12 or less are good - 6 or less is better. Many of the cheap charters take anywhere from 20-75 people at one time all to the same spot.