Spot's mum and dad take him to the beach. Spot builds sandcastles, and covers his dad with sand while he's sleeping! While exploring the beach, Spot meets another dog, and they play "chase".
Series 1 episode 13. First broadcast on 17th July 1987.
http://en.wikipedia.org/wiki/Spot_the_Dog
http://catalogue.bbc.co.uk/catalogue/infax/programme/LCHS059Y
http://www.tv.com/the-adventures-of-spot/spot-goes-on-holiday-a.k.a-spot-goes-to-the-beach/episode/223694/summary.html
Plus a short bonus clip of Andy Crane reading out some kids' birthday cards :)