Faronos the Mud Ship

Mud Ship 
This mastless, 30-foot-long ship is made of a fine reddish wood. The deck is 12 feet above the keel, and includes a small cabin to aft and a forward hold. These are both extraplanar spaces: The cabin is 20 feet by 30 feet with a stairway to the hold, which is 60 feet by 30 feet.
Only seven mud ships are known. Each has a name: Otonkolos, Faronos, Miktyr, Tarjana, Iquonabus, Ungulisar, and Uzrivoy. The vessels were created by powerful and evil elemental beings named Uzrith and Ayolvoy. If they learn that one of their craft has fallen into the hands of nonworshipers, they seek to eliminate the thieves.
Property (Attuned): When standing at the wheel, you can pilot the mud ship as if a normal craft overwater, underwater, and overland at a speed of 40 feet. If you have a talisman keyed to a named craft, you do not have to attune to that mud ship to pilot it.
In addition to your normal mode of respiration, you can breathe underwater while you stand at the wheel. Other creatures must stay in the cabin or the hold or risk drowning if they can’t breathe underwater.
The mud ship is unaffected by weather and is always seaworthy even while underwater. It otherwise has the traits of a small galley.
A mud ship sailing on land leaves the earth behind it undisturbed. It must sail around inclines greater than 45 degrees, though it can pass through as much as 500 yards of solid earth and stone (including artificial structures) once every ten days. After utilizing this latter ability, the craft must remain inactive for a full hour.
Rarity: Artifact.