Our group of mage is looking at building the Hermes, but there are still many seasons and sessions until then.
We are looking at creating a source of drinkable water on the Hermes, but possibly to have a floating covenant.
I found spell teleporting water from lake or stream with Arcane location. The effect level is a bit high (ReAq 54 for the complete effect) and lacks "flavour".
So I was wondering if it would not be possible to drain water from the clouds.
So we had the idea of enchanting a weather vane or a chalice with a ReAu, possibly a regular enchantment.
Then we had many questions:
Do we need a Muto or Aquam requisit (or both) ?
The base effect looks like 3 (affecting a weather phenomenon), then with a +3 for Sight, +2 for group (unless the effect drain one cloud at a time, but it looks labour intensive to target one cloud at a time), duration Mom (+0). So the base effect is ReAu 25
Then this is where it starts to be a bit unclear: a constant effect would clear the sky from every cloud, so a linked trigger +3 to a InAq detecting the level of water in the cistern seems the way to go, with 12 use a day (+4) seems enough. For a final effect of 32.
Are we missing something ?
The idea is that the water is raining around the weather vane or flowing out of the chalice as long as the spell is in effect.
I'd say a Base 3 will give you a heavy rain, but not a storm and a Base 2 would be a light rain.
I wouldn't do a constant effect. I would do a D:concentration with the item maintaining concentration or D:sun (both have the same effect as far as magnitude and timing). Even 1 use a day should be enough to make a the clouds rain. enough to fill the cistern...
The trouble comes when you're flying over a desert with a cloudless sky.
We also have a flying ship in our saga (powered by non-hermetic magics though).
As for water provisioning, keep in mind that:
a) a typical ship can hold enough provisions, including water, for weeks of travel.
b) if you can fly at 40mph you are almost never further than 1day/travel from some large body of water (potentially, the sea). So, instead of trying to catch rainwater, I'd just make something to filter water, and, push come to shove, every fortnight take a brief detour to "refuel". That's what we do at least
We know our plan is not perfect, but our elementalist cannot enchant the ReAq54 yet, so we are looking at less optimal but functional alternative.
Now, I know how to make rain, but we need to make sure that the rain fills the cistern:
ReAq 4 (move a liquid in a forceful but calm way), +1 Conc, +3 Sight, +2 move in an very unnatural way, Ind (if a consider the rain as a single weather phenomena as per Auram guideline, but I am not sure). So a ReAq30 to direct all the rain into the cistern.
With an additional +4 maintain Conc; freq 1/d, for a final effect of 34.
Alternatively, we were looking at building a chalice that would suck up the clouds around and condensate them into water.
So probably a ReAu to suck up the clouds, linked to a ReAu to turn them into clean water, with a linked effect, and probably a 3rd effect to tell to the Chalice when the cistern is full (InAq), to prevent flooding the covenant.
So the first effect would be:
Clouds-in-a-bottle: ReAu3, +2 Group, +1 Conc, +3 Sight. So ReAu 25, +4 maintain conc, +3 link trigger, 1 use/d. So ReAu 32
Milking the Clouds: ReAu3, +2 Group, +1 Conc, +1 Touch (since the first effect drags clouds inside the chalice). So ReAu 15, +4 maintain conc, +3 link trigger (when Clouds-in-a-bottle is in effect), 1 use/d. So ReAu 22. The thought was since it is a linked effect, the chalice does not have time to explode because of the clouds building inside since they are converted instantly into water.
The Everfull Cistern: InAq 3 (get an image of water and its immediate surroundings within range), +3 sight, +1 Conc, Ind. So InAq 15, +4 maintain conc.
Your average 1km3 cloud has about 500 tonnes of water, or about 550 tuns / tons of water. Roughly a million pints, 125,000 gallons. Don't drain those clouds too much.
"Send you army home, Duke, or I shall bring a cloud down upon you!"
"Oh? What threat is a mere clou - By God!"
WHAM!
MuAu
The Compleat Hail Storm, Level 15
R: Sight, D: Dia, T: Ind
Turns all of a single cloud to hail. A Finesse role is needed to achieve a desired hail size, otherwise the hail is assigned by the storyguide to grain to pea to small gravel sized. Coin sized hail requires a finesse roll of +6; nut-size hail +9; hen's egg sized hail +12, apple-sized hail +15, hail the size of a large fist +18. Small hail does +0 damage; nut hail +2; egg hail +4, apple hail +6; fist hail +8; all per round, to everything under it, for two minutes. This spell does nothing to place a cloud over a target.
(Base 4, +2 Sight, +1 Dia)
Not sure about the damage - it's based on stone damage from the missile chart, but heavy hail storms can shred light structures, mash crops, and kill herds.
Well, if you want to get all of a cloud and most clouds are indeed 1 km, you need size modifiers, as the standard size for auram is equivalent what is covered by a standard boundary.
MuAu already has a spell that does something similar, albeit within an existing rain storm, Rain of Stones. They are listed as being small stones, and keeping the damage roughly consistent, it can't be more than +0 damage.
Rain of Sand
MuAu (Te)
Level 30
Turns one ordinary sized cloud into many tons of sand, which immediately falls to earth, generally crushing everything beneath it.
(Base 4, +3 Sight, +1 Dia, +1 Size)
