If you're playing in a seafaring campaign, where you spend most of your time on a ship out at sea, can you basically use the draw moisture cantrip to pull an unlimited amount of drinkable water from the air and sea one pint at a time?
I'm aware that the spell limits drinking water from the air to a couple cups in humid environments, but there's an entire ocean that will instantaneously replenish that supply. Even if that doesn't work for more than a few cups, is there anything preventing the caster from drawing the water from the salt in the ocean to make fresh drinking water at the pint level?
I'd say absolutely 100% you can use the full pint the spell mentions (just target a bucket of seawater or a dunked cloth on a rope instead of the air moisture).
Where it would get GM involved is how long you can cast the concentrate cantrip without fatiguing yourself.
You can get a full pint in 2-A, which is great. But there's all the other steps such as targeting the seawater in one location, but depositing the freshwater in the main hold.
Even w/ all the outside hassle, I'd say it's easy to rule 2 casts a min, doable as your downtime work. x 60 min leads to 120 pints an hr, and using the 8-hr downtime day (doing real work but not fatiguing yourself) would be 960 pints of freshwater, by yourself. 120 gallons p day alone is def enough to sustain a whole ship.
If you have NPC crew to help carry w/ a bucket brigade, I'd give that a 2x.
If you really want to get immersed in the RP, don't forget that sea salt! It's a super valuable commodity IRL, and while being that easy to make via a cantrip would reduce/obliterate gp sell value, salt was still super important to a lot of people.
Assuming none of the intermediary steps, I calculated 75 gallons in an hour.
Do that with your morning preparations, and there should rarely ever be a need for additional drinking water aboard a ship.
Assuming none of the intermediary steps, I calculated 75 gallons in an hour.
Do that with your morning preparations, and there should rarely ever be a need for additional drinking water aboard a ship.
Think of the activity as a whole, not just the cantrip. The cantrip is just a tool that enables a new kind of work, it is not the whole task itself.
In specific, Draw Moisture was mindful with the 10ft range limit. That's not enough to bypass the physical labor.
How long would it take to (magic the water, then) carry a bucket from the side of a ship to dump into the main water storage?
Try to think about it in context, as a "replenish water stores" downtime job, not as a "constantly casting 1 spell" kind of deal.
Assuming none of the intermediary steps, I calculated 75 gallons in an hour.
Do that with your morning preparations, and there should rarely ever be a need for additional drinking water aboard a ship.
That would be a good moment to apply the concentration fatigue rule. Like casting frequently other spells like Detect Magic, you would be doing basically the same with Draw Moisture.
Unless a challenge of the campaign is dealing with getting enough drinking water, I'm not sure why it shouldn't be allowed.
And even if the challenge is getting enough drinking water, it is hard to rule that this isn't an effective way of succeeding at the challenge.