This is an activity for a group of 4 students. Students are given a constant rate of change of rain and are asked how many hours would they be willing to wait to cross the river. This problem included the concept of the y-intercept as the starting height of the water and the slope as the rain rate. Students are also asked to convert between feet and inches. The real world application allows students to have a variety of ways to think about and solve the problem with several correct answers based on their risk level.