The French naval policing boats Athos, which has a large machine gun on its front deck, and the unarmed Themis were sent to keep watch on waters between France and Jersey, French maritime authorities said. The deployment came after Britain on Wednesday directed two naval vessels, the HMS Severn and the HMS Tamar, to also patrol the waters around the island, a self-governing British Crown Dependency near the coast of northern France. French fishermen steamed into Jersey waters to protest new post-Brexit rules requiring them to submit their past fishing activities in order to receive a license to continue operating in the island's waters. French fishing communities claim some boats that have operated around Jersey for years have suddenly had their access restricted.