Dedicating adequate time for lab activities is critical for a successful Marine Science Curriculum. Even more important than the time allocated to performing lab is that the activities are academically appropriate and gratifying for the student. The most elaborate lab will not benefit the class if the activities are too involved or convoluted for most students to interpret the results. The module on water density highlights these fundamental parameters. All the concepts center around the effects of temperature and salinity on aquatic environmental conditions. The module consists of ten fifty-minute sessions that were designed for high school juniors and seniors. These lab sessions integrate geology, biology, math, chemistry and physics in order to give students the best overall view of the mechanics of water density. Each session includes teacher preparation information, student instructions, interpretation questions and extension activities. Most activities require little specialized lab equipment and can be easily modified to suit the academic level of any student. Along with teaching fundamental experimental procedures, students will also be introduced to procedures for field experimentation that will be implemented during subsequent student research trips. The module culminates with students preparing a formal lab write-up to help reinforce their understanding of the concept of water density.