This Technical Memorandum describes the first comprehensive study to quantify the increased drag induced by attachment of biotelemetry devices to sea turtles. Drag (ie, fluid resistance) refers to forces that oppose the relative motion of an object. Transmitters attached to the carapace of turtles as well as epibiont-related biofouling Rf the transmitter or its attachment method can increase hydrodynamic drag and affect lift and pitch during movements potentially altering an animal’s swimming behavior or workload. This report provides an empirical description of the increase in drag caused by multiple telemetry attachment configurations on different species of sea turtles. Additionally, we report on studies to determine the best location (ie that with the least amount of drag) on a turtles’ body for each telemetry attachment configuration.