Mr. free101girl and I are going to be visiting NZ in March and are considering a daytrip from Auckland to try black water rafting at Waitomo Caves. It sounds like a unique experience. Kiwis do come up with the coolest ideas. (I'm looking forward to Zorbing at Rotorua too.)

Anyway, has anyone here tried black water rafting, and if so, how tough is it physically? I have an adventurous spirit (no claustrophobia or fear of jumping backward into the water, etc.). However, I do have bad knees and the descriptions I've read mentioned some "clambering" over rocks in the dark within the caves. I can walk for miles on flat ground, but steep hills and stairs get to me after a bit. (After about 3 big flights of stairs I'm in some pain... 10 flights in a day and I'm done.)

Should I skip the black water rafting? My husband will definitely do it whether I go along or not. If it's too tough for a gimp like me, I can always do one of the regular cave tours and wait for him. Advice?