Teachers find the implementation of fieldwork challenging. Therefore, this study investigates two teachers' implementation of theoretical guidelines for student-centered fieldwork activities, following their participation in a professional development course focusing on earth science fieldwork pedagogy. Video observation and instructional artifacts were collected and analyzed using various indicators, including the quality of the learning activities, the types of "talk," teacher questions, the focus of student initiatives, and how the students engaged in the learning activities. The results revealed that the teachers implemented the guidelines through two totally different fieldwork designs. In one case, called the "linear teacher-dominated fieldwork design," there were clear differences between indicators in the classroom and those in the field. In the field, teacher dominance was reduced, and students were more active and focused on the content. In the other case, the teacher developed an "integrated inquiry-based fieldwork design" that involved alternating between the classroom and the field as well as using inquiry-based learning activities. The teacher had a reduced role in terms of talk and questioning, and to a large extent, students showed deeper engagement. Notably, in both cases, the learning process and student engagement deteriorated during the follow-up phase. Finally, on the basis of these findings, recommendations for fieldwork designs are discussed.