Dozens of whales are entangled in fishing gear each year which often lead to serious injuries or deaths. Because the number of entanglements has increased in recent years, agencies have implemented policies aimed at protecting the whales but altering fishing regulations. Therefore, to protect both the livelihood of the fishermen and the lives of the whales, the National Oceanic and Atmospheric Administration (NOAA) tasked our team with designing an engineering solution. Research suggests that it is the feet of slack line in the fishing gear that entangles whales, so our team has developed a whale-safe fishing method called “TightLines” to eliminate this excess slack. Recognizing the fishermen’s need to have a cheap and quick to implement solution to maintain speed and efficiency when fishing, our simple system consists of a self-tensioning system composed of a basic pulley (an O-ring) and a counterweight connected to the buoys and crab trap. This design enables this system to maintain tension as the depth changes, thereby reducing the likelihood of whale entanglements and allowing the fishermen to operate as close to normal as possible.