 Their robust iron hulls meant that they lingered on as diving tenders, barges and lighters, with five of them working into the 1920s.The hull of "Medway" lies in shallow water in Bermuda and is visible on satellite imagery.The "Medina" class were a development of the Rendel (or "flat-iron") gunboat, a series of small vessels with low freeboards that mounted a small number of relatively large guns.