Clover, bell of three,
Welsh Patrick, coracle and Gaels,
. . . Sacred trinities.
Legend (dating to 1726, according to the OED) credits St. Patrick with teaching the Irish about the doctrine of the Holy Trinity by showing people the shamrock, a three-leafed plant, using it to illustrate the Christian teaching of three persons in one God. For this reason, shamrocks are a central symbol for St Patrick’s Day.
The shamrock had been seen as sacred in the pre-Christian days in Ireland. Due to its green color and overall shape, many viewed it as representing rebirth and eternal life. Three was a sacred number in the pagan religion and there were a number of "Triple Goddesses" in ancient Ireland, including Brigid, Ériu, and the Morrigan.
The coracle is a small, lightweight boat of the sort traditionally used in Wales but also in parts of Western and South Western England, Ireland (particularly the River Boyne), and Scotland (particularly the River Spey). The word "coracle" comes from the Welsh cwrwgl, cognate with Irish and Scottish Gaelic currach.
Designed for use in the swiftly flowing streams of Wales and parts of the rest of Britain and Ireland.