afterglow aqua architecture attraction background beacon beautiful blue building cloud coast coastal coastline design dusk graphic harbor hope horizon icon illustration landmark landscape light lighthouse maritime nautical navigation ocean red rock safety sea seascape shipping shore sky sunset symbol tower travel vacation warning water white access-limited advice advising alert appropriate-behavior appropriate-behaviour authorised-entry-only authorized-entry-only black boots care caution clothing concern construction-site danger dangerous directions eye-protection feet footwear helmets information informing injury limited-access peotective-equipment protect protection protective restricted restriction restrictions risk risks risky sign unauthorised unauthorized visibility warning-sign workers workmen