beach blackpool channel coast dawn distance distant England Great Britain light line low natural nature pattern ridge rill sand shore space texture tidal tide water algae coastline Cornish cornwall english holiday leisure ocean resort rock sandy sea seaweed surf vacation waves bay family fun horizon Jetty kent landscape play relax sky summer tourism wave deck chair heat honeymoon hot idyll lonely relaxation sun sun shade sunshine two unpeopled Cromer drift environment erosion gravel groin groyne longshore norfolk planks posts protect protection sustain wood wooden boulder cliff low tide