z.....back to your point about landings and portages.  I agree with you that these may present the greatest challenge.  Some of these can be down right treacherous especially if slippery.  After all it's not like walking down a sidewalk or climbing a few flights of stairs.  I've taken enough falls and dunks myself.  I would also think that it would take "considerably" more time for almost anything to happen.  Per Jimbo, I'd be having the conversation. Perhaps a trial run?