Astrology - Grand Water Trine, two different views

Sun: 29'Cancer
Moon: 18'Capricorn
1 Day to Full Moon

So.  A friend of mine emailed a group we are both part of on Wednesday (good day for mass emailings, being that that's Mercury's day) regarding a major astrological configuration coming exact this past Thursday.  Specifically, Mars + Jupiter in Cancer, Saturn in Scorpio and Neptune in Pisces, all coming to trine one another for the Grand Water Trine pattern.

Now, the Grand Trine happens fairly often - I have one in my own natal chart, across the Air signs.  But usually when it happens it involves the fast-moving Moon and only lasts for a few hours, or it'll split elements (one planet sitting in a different element than the other two when it occurs close to a cusp).  It's a lot rarer to get the much-slower social and generational planets involved across the same element: Jupiter, as the fastest of those three, still takes about a year to transit the 30 degrees of just one sign, and they stay together for a bit when it happens both prior to and after the most exact point.

I find it interesting to hear how the same aspect patterns can spark totally different takes on it.

Water

The local Wiccan circle had a meditation last night on water.  I find myself in the unusual position of being able to speak with some authority on the subject.

The main correspondences are clear to anyone who's studied for a decent amount of time.  The Moon, Venus, Neptune.  Cancer, Scorpio, Pisces.  Moonstone, aquamarine, opal, obsidian, silver and quicksilver.  Willow, yew, rosemary, lilies of all kinds.  Animals that live on or near the water: that's a pretty wide variety from dolphins to dragonflies.  Ocean magick, river magick, wishing wells and mirrors.

What could water magick be used for, though?