He was concerned that if they did too much planning for their 4,000 mile canoe trip, it would've taken the adventure out of it.
"Altogether, Dan and Marc paddled (and walked and towed and portaged) for nearly seven months. They inadvertently notched the first ascent of a 100-mile-long canyon peppered with class IV and V rapids—at an achingly slow 1 mph (and that on a good day!). But humble Dan has no regrets about their level of planning. In fact, he encourages that kind of spontaneity from other would-be canoe explorers."