Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Was great now very out of date

Almost everyone of my group of Grand Canyon boaters owned this guide and it was great but now it is so dated that it is hard to recommend. Many of the rapids have changed and new ones have formed from the early 1990s. The flows have also changed. It would be great if someone would bring this up to date and print it on waterproof paper.