Thanks...I'll be wearing a full 7 mil, no farmer john. I would normally wear about 18lbs when diving with this suit.
" The guides tend to get hacked off when your fins breaf the surface"
I didn't even think about that. The last time I was there I was free diving down trying to get a photo of that huge Tarpon at the bottom of the channel. No one ever said a thing but I'm sure they had to see me free diving in the channel. A fine would be a bummer for trying to harass a tarpon...haha. I was also able to get some up-angled photos of Manatee like that.
Gary,
If you get this message in time I just wanted to let you know that the conditions with the manatee today (Feb 8th) were fantastic. It is a very dynamic and changing environment there - unfortunately the river was wracked by unusual storm surges in the early 1990s that killed most of the fresh-water aquatic plants that used to keep the water crystal clear. Now invasive Lyngbia sp algae has taken over and the clear water/manatee combination is so hard to find but it is still there.
Today was one of the top 20 days I've had there. I had very good friends that brought their polite children (4 of them), and they were all "beaming" about what a magical experience it was. Plus is was so great today because the photographers had their space with the manatee (there was Seacam, Subal, Aquatica, Nexus and Nikonos there today), it was very clear and not stirred up with very polite and professional acting photographers. Best of all the manatee were undisturbed. There weren't as many manatee as yesterday when I went, today I estimate there were about 60 manatee in one area and more in surrounding areas and sanctuairies. Yesterday I counted over 80 in the same area but viz wasn't as good - too many manatee is not good for viz either cause they stir it up............ 
Chris from Bird's Underwater took my friends and their children to a different area near but away from where the photographers were today! This is what the best guides do because the "famlies" just want to wonderful experience/playful manatee, they don't care so much about the absolutely clear water. Plus around the corner was a littler deeper and not able to be stirred up much. Happy photographers and happy family and happy manatee.
Unfortunately this only happens during weekdays, and now rarely at that. I always tell people never, ever go on a weekend, plan ahead....., this is what my friends did, we picked a Thursday for them and their first manatee encounter was magical, they got a great video with no one else in the water - good pics from me, and the photographers around the corner were undisturbed - along with undisturbed manatee which is most important!!
There will be a change later this year limiting the numbers of people in the water with the manatee - this is much needed.
Still until then you should have a good tour on Feb 12th. Conditions are good, tide will be a bit low in the am that day, but the water level is higher so it might not matter as the river doesn't always follow the tide charts.
I would encourage you to wear enough weight to sink slowly rightside up or horizontal with fin tips up. Yes any sort of freediving is not the best way. It makes manatee watch volunteers nervous cause they think you are diving down and pursuing a manatee (against the law), and it is really not a good position for pics either and can be distracting to manatee.
Why don't you wear a weight belt with enough weight that you can remove some if you are too heavy? You should be able to tell right away in a quick test near the boat. If you hold air in your lungs at the surface, let 1/2 out and slowly sink you will get great pics. Move slowly and calmly and you won't upset manatee or fish and wildlife people!
There are lots of manatee at Crystal River right now and conditions are good, a lot better than last February - considering all the factors.
Best and good luck, Carol
PS also here is a neat new book to get to educate yourself about the manatee - incredible book by the foremost experts, on manatee in the world - (and hands-on experience, not "ivory-tower")! Here it is at Amazon but Bird's has it also:
The Florida Manatee: Biology And Conservation (Hardcover)
by Roger Reep, Robert K. Bonde
http://www.amazon.com/Florida-Manatee-Biol...n/dp/081302949X