Depends how far you are from the city when you open the gate and if the Nautiloid is coming from up-hill, down-hill or if the city is on a plane.
If the Nautiloid is coming from down-hill maybe you will flood some countryside, but the city itself should be safe. If the city is a harbor, the Nautiloid may be coming from direction of the sea and you would have no damage whatsoever. (Besides a few fishes killed by the pressurized water falling from above).
If the city is in a plane you could flood a little bit the surrounding countryside, but after all 1.7B liters are just 1.7m cubic meters, which is a 17cm thick layer of water in a 10km2 (square area with ≈3.3km side).
If the Nautiloid is coming from uphill … that may be a problem.
In that case the party may decide for a less drastic option, opening the portal at a depth of a just few hundred meters. You may have enough pressure to destroy the vessel without so much collateral damage.
On the bottom of the ocean the pressure is ≈500 bar. If the gate has a diameter of 10m in 1 min will flow ≈2Billion liters of water, something like 1K swimming pools.
Enough to flood many times over the Nautiloid and to make it crash.
The Nautiloid would not flood--it would merely cease to exist. The flow rate of the water in this situation would be defined as Flow Rate = π(opening diameter)^2 x [(2)(oceanic depth)(gravity)]^(1/2).
Calculating gravity on D&D is a bit hard since you fall at a pretty standard rate. However, if we just look at the 0-6 second timeframe where you fall 152.4 m from a starting velocity of 0, we can use S = S0 + V0(t) + (1/2)(a)(t)^2 to calculate the rate of gravity on a D&D world. Or -152.4 = 0 + 0(6) + (1/2)(a)(6)^2. Or -152.4 = 18(a). Or 8 = -8.467 m/s^2. (which means the gravity on D&D worlds is slightly less strong than -9.8 m/s^2 of Earth).
We now know the opening diameter (6.096 m). We do not have a good figure for depth of a D&D ocean, so let us use the average from Earth - 3,700 m. And the Gravity. So, we know know Flow Rate = π(6.096)^2 x [(2)(3,700)(8.467)]^(1/2). = 29,222.706 m^3 per second in volume. 29,222,706 liters per second for up to one minute - 1,753,362,360 liters total--that is about what you wrote.
Here is why flooding is not going to come into effect - velocity = [2gh]^(1/2). Here, that means we are looking at a velocity of 250.314 m/2 for the jet of water. 559.930 miles per hour for fans of imperial units. That means the 1,753,362,360 liters (463,189,333 gallons; ~708 Olympic pools) of water are not merely cascading over the vessel - they are hitting the vessel at the cruising speed of a passenger airline. Even a quick hit at that velocity would obliterate most things--a prolonged exposure for a minute would annihilate it... and everything below it (not to mention the destabilizing effect of the flooding which, at those volumes of water, would cause substantial damage to the city itself). At that point, it really would not matter if you "do it before the vessel is above the city"--it is very unlikely you will be able to "avoid damage".
Answered above, sorry I forgot to quote you Great observation ☺️
I don’t know if you have access to 9th level spells… If you don’t have it teleport the party to a place where you can buy one (have the government of the city you are protecting pay for it). You just need one: Gate.
Once the Nautiloid arrives dimensional-door your party on board.
Dimension Door only has a 500 foot range and if you can't see your destination you risk choosing a spot that's already occupied, in which case the spell fails and you take damage.
I meant the party to use Dimensional door to go on-board and find in person an unoccupied spot.
I don’t know if you have access to 9th level spells… If you don’t have it teleport the party to a place where you can buy one (have the government of the city you are protecting pay for it). You just need one: Gate.
Once the Nautiloid arrives dimensional-door your party on board.
Dimension Door only has a 500 foot range and if you can't see your destination you risk choosing a spot that's already occupied, in which case the spell fails and you take damage.
I meant the party to use Dimensional door to go on-board and find in person an unoccupied spot.
Yeah, and if you can't see the location where you're teleporting to, which will generally be the case if you're teleporting from the ground to a Nautiloid, it gets risky.
Rollback Post to RevisionRollBack
Find your own truth, choose your enemies carefully, and never deal with a dragon.
"Canon" is what's factual to D&D lore. "Cannon" is what you're going to be shot with if you keep getting the word wrong.
I don’t know if you have access to 9th level spells… If you don’t have it teleport the party to a place where you can buy one (have the government of the city you are protecting pay for it). You just need one: Gate.
Once the Nautiloid arrives dimensional-door your party on board.
Dimension Door only has a 500 foot range and if you can't see your destination you risk choosing a spot that's already occupied, in which case the spell fails and you take damage.
I meant the party to use Dimensional door to go on-board and find in person an unoccupied spot.
Yeah, and if you can't see the location where you're teleporting to, which will generally be the case if you're teleporting from the ground to a Nautiloid, it gets risky.
We are speaking of destroying a nautiloid occupied by an invading mind-flyers army, not of partybanging a stupid bugbear.
There are no free meals 🤷🏻.
If you doubt you can make it and you have spells to spare you could simply cast Invisibility on yourself, then Fly, Passwall and you are in. You cast gate, Passwall and Fly are still casted and you simply let the Nautilod pass through you.
One important fact, the players are not the PC's and the PC's are not the players so as a player ask the GM what you know, what are your resources, what has been done in the past and what are rumors of what has been done or can be done? I like to give the GM a heads up that I use this method so they can be prepared with info a head of time.
Why do I use this method? Well quite simply I am acting as the PC and I try and not use my knowledge of things vs what the PC's knowledge of things are.
So, how did the city deal with teleporting in the past? How did the city deal with enemy ships, dragons and other big bad's in the past? And other basic questions you ask can help you make the best choices (or at least the best worst choice).
Also I have tended to realize city design, operations and defense are advanced topics of game design and GM's may not be skilled in this area, ie high magic game city might be a modern one and in low magic people may have to go to an area to dump their chamber pots and deal with other basic necessities in a non-optimal way.
Also be sure that teleport and other such rules are being enforced, like the spell and or ability describes (note GM's make mistakes so cut them so slack as they have a lot on their to do list) but if your game is more story based (things happen because the GM needs them to happen no matter what the rules say) then you may have an issue or you may simply have fun dealing with the unusual way some of the other "people" in the game worlds magic and abilities work.
Good Luck
Rollback Post to RevisionRollBack
To post a comment, please login or register a new account.
N
Answered above, sorry I forgot to quote you Great observation ☺️
I meant the party to use Dimensional door to go on-board and find in person an unoccupied spot.
Yeah, and if you can't see the location where you're teleporting to, which will generally be the case if you're teleporting from the ground to a Nautiloid, it gets risky.
Find your own truth, choose your enemies carefully, and never deal with a dragon.
"Canon" is what's factual to D&D lore. "Cannon" is what you're going to be shot with if you keep getting the word wrong.
We are speaking of destroying a nautiloid occupied by an invading mind-flyers army, not of partybanging a stupid bugbear.
There are no free meals 🤷🏻.
If you doubt you can make it and you have spells to spare you could simply cast Invisibility on yourself, then Fly, Passwall and you are in. You cast gate, Passwall and Fly are still casted and you simply let the Nautilod pass through you.
Fly and Invisibility both require concentration.
Find your own truth, choose your enemies carefully, and never deal with a dragon.
"Canon" is what's factual to D&D lore. "Cannon" is what you're going to be shot with if you keep getting the word wrong.
One important fact, the players are not the PC's and the PC's are not the players so as a player ask the GM what you know, what are your resources, what has been done in the past and what are rumors of what has been done or can be done? I like to give the GM a heads up that I use this method so they can be prepared with info a head of time.
Why do I use this method? Well quite simply I am acting as the PC and I try and not use my knowledge of things vs what the PC's knowledge of things are.
So, how did the city deal with teleporting in the past? How did the city deal with enemy ships, dragons and other big bad's in the past? And other basic questions you ask can help you make the best choices (or at least the best worst choice).
Also I have tended to realize city design, operations and defense are advanced topics of game design and GM's may not be skilled in this area, ie high magic game city might be a modern one and in low magic people may have to go to an area to dump their chamber pots and deal with other basic necessities in a non-optimal way.
Also be sure that teleport and other such rules are being enforced, like the spell and or ability describes (note GM's make mistakes so cut them so slack as they have a lot on their to do list) but if your game is more story based (things happen because the GM needs them to happen no matter what the rules say) then you may have an issue or you may simply have fun dealing with the unusual way some of the other "people" in the game worlds magic and abilities work.
Good Luck