Magic & Psionic Submersible

[Andor the Great & Powerful]

Sounds like fun right? But, who wouldn't want a vessel to be magically enhanced as it was constructed with magic devices, (and psionic gadgets if you do that stuff). I was thinking that it would have a magic engine, for fuel simplicity.

I set one up in the campaign that I've been setting up for, and have found no reference to RPG-ize such a vehicle, and it's functions. Most of its construction was done by a veritable army of Uber-Powerful, High-level, Heroic NPCs. 99% of which the PCs will never meet because they're all dead, for one reason or another.
For the sake of the Campaign i won't be "stat-blocking" the vessel... yet; but it is about {98 squares (35ft x 70ft x 35ft high) and 1 deck(inside)} the vehicle needs a simple defense to use against the main creatures it'll face and have to defeat: Clockwork Leviathans/other denizens of the deep. I cannot figure out exactly what kind of magic device would be best, aside from one that deals electricity damage, and only to creatures & etcetra that are touching(or in direct physical contact with) the exterior of the Submersible. (assume CL 20th for the crafter of the device).

Otherwise What are your thoughts on such an intricate device.
I'll try to share more as i digitize my campaign.

Exile Isle Plot Spoiler:

for the sake of the story: the Shelterton Submersible is constructed From a combination of Mithral, Magically Strengthened Brass, with an outer hull of Adamantine. it is designed to withstand the deepest depths, and the most deadly predators without succumbing to the corrosive nature of saltwater. its construction is as a result of the Massive deposits of the various metals, along with various gems and crystals, naturally found on the island (because teleportation off the island, and plane shifting is negated by the magic of the island). the Vehicle was hidden by the Dwarves, and Gnomes in the Depth of the mine.

[Andor the Great & Powerful]

Okay... i thought i posted this long thing about a submersible that i was wanting to use in my game, but it's not showing up...

[Vutava]

Eberron had a submersible vehicle, but I don't remember seeing a statblock for it.

[Andor the Great & Powerful]

i think i have Eberron... i'll look when i get the chance... where might i find it?

[LazarX]

Why would you need psionics when you have magic?

[Slithery D]

There was an old AD&D 2nd adventure that had a submarine traveling the elemental plane of water that was powered by a bound water and fire elemental in an engine compartment brought into contact to produce steam.

[Dave Justus]

I ran a game where I gave the PCs a submersible in 3.5 Eberron. I believe I just made up the stats, basing in on the magically powered surface ship from the Stormwrack book I believe.

I gave in fairly minimal defenses originally, I recall it being just 3 ball turrets with underwater crossbows (you could load/fire them while being inside the ship.)

Later the group added some more powerful weaponry.

Ever just basic crossbows (or ballista if you want to up the damage a bit) work pretty well though, especially if you have specialized ammunition. Obviously regular enchanted arrows would work, but in addition something similar to a javelin of lighting would be possible for more serious problems.

In my game though, the most typical response to the ship being in danger was for the PCs to go out through the airlock and beat up the bigger fish personally.

[Vutava]

Andor the Great & Powerful wrote:

i think i have Eberron... i'll look when i get the chance... where might i find it?

It's mentioned on p40 of the Explorer's Handbook.