Instructional support is fundamental to successful implementation of Inquiry-Based Learning (IBL) in various educational settings. Although research indicates that instructional support can lead to learning gain and achievement of inquiry strategies, it does not explain why the same level of guidance for students with relatively the same level of domain knowledge can lead to major differences in their performance and learning gain. To investigate this issue, we performed a descriptive observational study on a group of undergraduate students (N = 10) during their inquiry learning process in a physics simulation. Our results indicated that employing strategies such as setting goals, confronting misconceptions, testing prior knowledge, collecting evidence, reasoning, and inferring by examining various conditions contributed to high learning gain in students. Additionally, instructional support was found beneficial by all individuals -- with both high and low learning gains. However, low gainers tended to benefit more from explicit explanations and direct modeling. The results imply that some specific cognitive and metacognitive strategies are required as prerequisite inquiry competency for successful use of simulation tools and tutor guidance in a simulation based inquiry learning. These strategies can probably be developed through training workshops, instruction, and appropriate scaffolding during various phases of inquiry learning.