Comment the statement '' Upper reaches of the Thames would not allow the navigator of the boat sufficiently''

The first list we made out had to be discarded. It was clear that the upper reaches of the Thames would not allow of the navigation of a boat sufficiently large to take the things we had set down as indispensable; so we tore the list up, and looked at one another!

In this quote, we see that the list the men had made of items considered indispensable (things they couldn't do without) was so long that they wouldn't fit in the type of boat they'd need to travel on the Thames. Thus, they will need to trim their list considerably, and we can infer that much of what the deemed indespensable was not actually necessary.