beach dunes pools sand Sandbar tidal tide water blue gray sea Stingrays swimming white sand aqua white Barmouth boats coast estuary forest Gwynedd harbour hills hulls low masts moored mudflat wales welsh yachts agitated battle choppy coastline current Devon England english exe flow Great Britain natural nature river turbulent waves channel guidance guide navigation sign warning birds colors colours dune-flora grass grasses green greenery growing growth gulls levels low tide ocean ocean edge ocean waterline pelicans plants receded receding receding tide rough salt-resistant sand-dunes scrub seabirds seagulls tides vegetation waterbirds waterline flora accommodation action activity boat buildings contrast culture expensive fast homes houses leisure light luxury manoeuvrability mobility motor-boat moving outdoors pleasure power recreation ripples rippling river-views riverside scenery scenic shade shadow shadows shrubbery shrubs sunlight sunshine surfaces transport transportation travel trees views wake waterways