The aim of this work is to describe the development of an innovative cleaning tool for underwater applications, to be used in particular in the field of underwater archaeology. This work takes place in the framework of the EU FP7–funded ARROWS project. ARROWS adapts and develops low-cost autonomous underwater vehicle technologies to significantly reduce the costs of underwater archaeological operations, covering the full extent of archaeological campaigns. The project deals with underwater mapping, diagnosis and cleaning tasks. During the first half of the project, a cleaning tool prototype, able to be mounted on underwater vehicles, has been worked out: this cleaning tool will be exploited not only during research missions but also for the periodic monitoring, controlling and maintenance activities of well-known underwater archaeological sites (e.g. periodic cleaning operations).