The "Titanic" caught the attention and imagination of the public when, in 1985, the sunken ship was discovered 370 miles off the coast of Newfoundland (PBS, 2012). Since that time, scientists have conducted numerous expeditions using high-resolution SONAR working in tandem with remote-operated vehicles (ROV) to collect information used to produce precise three-dimensional maps of the shipwreck (Cohen, 2012). Ironically, the SONAR technology used to help discover the "Titanic's" final resting place was developed just a few years after the ship's demise. Had the ship's captain had SONAR aboard, the tragic event may never have happened. Scientists use SONAR to help sailors navigate by making maps of underwater hills and valleys. Typically, a research ship with SONAR crisscrosses the ocean in a grid pattern, marking the water's depth at corresponding latitudes and longitudes. By measuring the distance from the water's surface to the sea floor, scientists are able to mark elevations, visualize the terrain, and produce three-dimensional maps. This form of underwater cartography is called bathymetry. Bathymetric technology has allowed for the discovery of hidden seamounts, volcanoes, reefs, and other objects, which has aided in the smooth operation of nautical transportation (National Geographic Society, 2012). Teaching students about SONAR and other methods for collecting underwater depth is a great way to help them understand how communication and transportation technologies are interdependent. Because SONAR may not be readily available in the classroom, the teacher may want to consider having the students use the pole or line method to collect data and then enter the data into a computer to display their results. Using a printer-paper box with a lid, plastic containers of various sizes, and Microsoft Excel®, students can have hands-on experiences learning about ocean-floor topography. By exploring bathymetry, content standards such as communication and transportation technologies can be explored and discussed. The activity presented in this article introduces students to bathymetry while reinforcing data collection, graphing, and computer skills.