Abstract: A scuba cylinder retention rack designed to be portable and keep the cylinders in an upright position during storage or when transported. The rack was designed for use in the bed of a pickup where a permanent mounting edge already exists, but can be used anywhere a similar edge or fixture is found or installed.The vertical tube from the headpiece fits inside the vertical tube of the base and meets the spring that is housed in the base tube. When the headpiece is forced downward, the spring is compressed and the unit can be placed under the edge of the pickup bed or similar fixture. As the downward pressure on the headpiece is released, the unit expands and the edge holder on the rear of the headpiece contacts the mounting fixture. The expansion force of the spring keeps the unit securely in place. The cylinders can then be positioned in the unit and secured with a rubber strap.