How thick of stuff can a sickle bar mower cut?

I'm considering getting and using a sickle bar mower to mow along the sides of a stream bed on my farm, since my belly mower doesn't quite get to the edge (and it's a 3 foot drop for me on the tractor if I get too close!). Question is, some of the stuff growing along the stream bed is grassy plants, some is brush - thorny plants, light climbing vines (thin), etc...nothing wider than 1/4 inch as best I can tell. What do you folks think of using a sickle bar mower for this? Anyone have any other ideas on how to do tihs safely and with minimal damage to myself or my tractor?

Thanks
Pete in PA

I once had a very interesting experience mowing along a river bank. If I was to do it again, especially with the sickle bar facing toward the creek rather than away from it, which is what saved my butt, I would first walk along the bank. I would be very, very sure that there were no gullies or sags that the tractor could fall into and start rolling toward the creek. Or rocks or other sudden protrusions that might throw the rig toward the creek.

However, that is the way to do it, and you should not have problems cutting shrubs & such up to 1/2 an inch.

I do not understand the guy who made the comment about it being better than driving parallel to the bank???

--->Paul