In a bowl, combine yogourt, coconut milk, honey and chia seeds. Divided in 4 cups or glasses, refrigerate overnight.
Place sea buckthorn with water and sugar in a small pan over high heat, stir and bring to a boil. Reduce heat, and simmer until sugar dissolved. Remove from the heat, place it int the jar of a blender, puree until smooth. Pour through a fine sieve, discards solid. Refrigertate for up to 5 days or freeze up.