Fortunately we don't get the beach "Tar" to the extent you used to in the 1950's and 60's. Most of it wasn't "tar" but heavy bunker fuel oil from ships losing it over the side either accidentally or deliberately when cleaning tanks or bilges and for a good time after the war a fair amount was still escaping from various war casualties. When cold it was fairly solid but stuck on a beach pebble in the summers sunshine it got sticky enough to be a right nuisance and most mothers would take something to clean it of their children. Vessels using it are getting rarer as emission targets get imposed more and more and dumping it over the side has been banned for years.
G.Harman