What line are you going on? I did this excursion in Jan. 2003 on Celebrity's Constellation. Just tonight I was speaking with my partner and told her that my absolute, hands down, best day this year was the day we did the stingray swim. I had an unbelieveable experience.
I cannot recall the name of the place we did this at, though, the crew was very friendly and chatty and if I recall correctly, there is only one place on the island you can do this, so hopefully I'm writing about the excursion you are debating about.
We arrived by van, and the ride took about a half hour from the port. Our driver gave a nice commentary about the island when we passed things as we drove. We boarded motor boats (the group of us split into 2 boats) and headed to the "pen" - maybe a 10 minute boat ride - but perhaps not even that long. There was a floating dock in the middle of all this water. It was beautiful. We were helped out of the boats onto the dock (my partber isn't such a good swimmer, so the crew picked up on her nervousness and was there to assit her any time she needed it). We climbed down a pool ladder (maybe 4 steps?) into the pen, and the stingrays were in there! We were told that they don't bite (unless you step on them) and to drag our feet through the sandy bottom and that would eliminate us from inadvertently stepping on them. It was so weird to feel them tickle your ankles as they swam by.
The water as perhaps 4 - 4 1/2 feet deep. You could definitley stand in the water without having to swim. Thad made my partner much more comfortable. This outfit also provided snorkel masks and pipes and we were able to snorkel and watch the stingrays swim around. There were also some huge lobsters to check out and some really cool shells and fish in the pen. The staff really made this excursion. The guy who owns it is lucky to have found such gentlemen to work for him. Most of these guys were in their 20s and would "grab" (not harmfully) a stingray and would "bounce" it (move it in his arms from side to side). You could then feel it and pet it. It was so COOL! I loved it! Then, as you got more comfortable, you could then "bounce" the stingray yourself. I had such a blast doing it, and if the stingray swam out of your hands, there was also a staffer there to grab another for you and help you with it.
At the end of the time in the pen (maybe an hour or hour and a half into it?) there was a photographer there who took digital pictures of you holding a stingray. You could do it individually or as a group. (We did both) We then boarded the boats back to the house and were served rum punch. I had rum punch every day on that cruise - but this was by far the best. [So, if those wonderful guys in Antigua are reading this glowing review, be kind and email me that receipe please! I had asked for it when I was there, but had a few too many rum punches to remember correctly. All I recall is that it seemed so easy...]
While you had your rum punch, the digital pictures were developed and you could buy them for something like $10 a piece for a 5x7. I bought all three.
Needless to say, I had a great experience and would recommend this to anyone.
I will say that if you are very squeemish and think you will get freaked out, don't bother doing this. One woman on the excursion got pressured into partipating by her husband. She kept shrieking and jumping and that just made her look foolish - and kept distracing me!
If it's possible to have any other questions on this, feel free to email me.