A couple of tips that I have found helpful when doing these review scavenger hunts, such as this one or my First Ferris Wheel scavenger hunt, is that I may need to preview or review certain questions as some kids may not be secure remembering how to do something taught earlier in the year. As the kids are doing the scavenger hunt, I make sure that I am available to answer a student's question or give support when needed. While other students are participating on their own, I get to reteach mini-lessons with those who need it. I never grade the scavenger hunt answers. We review all the questions and answers together. This is why it is a review. It is a learning experience. Students can explain how they got an answer and this is a great time to reteach a point if many students struggle with a question.
You can find The Titanic scavenger hunt here.