noun

1. A vessel made of a refractory substance such as graphite or porcelain, used for melting and calcining materials at high temperatures.
2. An extremely difficult experience or situation; a severe test or trial
3. A place, time, or situation in which different social forces or intellectual influences come together and cause new developments.

The first is a clear (easy) metaphor, or perhaps the melting down of the next 2 to fit into one said vessel. The sea is not always calm, in fact most times not, there are storms and all in between, so cherish the times where the tide laps like a sleepy kitten and the vast reaches of molten water are like satin glass, where a pebble thrown births perfect circles outward from each other, pacing in uniform to the horizon…