Not aware of any rafting trips down the Black River but I know of some trips up the river (Black River Safari). Most excursions will travel up the river on a barge boat while some other off resort services will bring you up in a fishing boat. Not really sure about wanting to be in a raft when the Croc comes up to vist you!
The barge will turn around at the bridge as it can't go under it while the fishing boat will travel up farther and possibly to the Bar From No Where.
The Black River tour is not a rafting trip, it is a boat trip. You will see beautiful scenery and many exotic birds in addition to plenty of crocs of which you can feed!
Would be much to dangerous to go rafting among cros!
We did the Black River as well as the Appleton Rum tour and YS Falls all in the same day. I highly recommend this excursion. The crocs come right up to the boat, my husband even touched the tail of one of them. The river is beautiful. I tried to attach a couple of pics, I hope it worked.
If you are in the area of Montego Bay, you can choose from the Martha Brae River and the River Lethe. Martha Brae River Rafting can be found online at www.jamaicarafting.com, and Jamaica Tours Limited, which conducts trips down the River Lethe, can be reached at (876) 953-3700.