Deployable slackline systems are disclosed which can support a slackline at a desired height and nominal tension. The disclosed systems may maintain one or more slacklines and can adjust height and tension of individual slacklines while the slacklines are in use. The disclosed slackline systems are stowable; tensioning and termination assemblies of the slackline system can each fold into a compact housing having a height substantially less than a vertical range of motion of the slackline. The disclosed slackline systems can be implemented in aquatic or non-aquatic performance environments such as on cruise ships or other hospitality settings.