Water cross

Water. Hence the mermaid (a Breton interpretation of Morgane? Or is she Dahut, the daughter of King Gradlon who threw her in the waters that engulfed the city of Ys and let her drown, because the so-called saint Guénolé advised it in a typical example of saintly behaviour?), watersnakes, salmons ('Wisdom' in Celtic lore), and the grail as holder of the Water of Life (but isn't that another name for whisky nowadays?)