Not all ghosts represent animate objects (like people or animals).   Inanimate objects such as ships, trains, automobiles and aircraft are historically numerous.  Many of my counterparts in this field consider this difficult to fathom based on their beliefs in spiritualism or other similar causes for paranormal activity.

On the other hand, since I see the entities we investigate as consisting primarily of energy I don't think it’s as hard to explain.  But regardless of your school of thought, there are difficulties in explaining what have come to be known as inanimate hauntings.

Clearly inanimate objects like those discussed above were never “Alive” in any common use of the word. That being the case there is no consciousness or soul, which makes many people question their ability to survive after the end of their physical existence.

The most common theory is that we’re not seeing or hearing true manifestations in the traditional sense, although if forced to categorize them, I think we’d consider them most similar to residual hauntings.  Meaning that they’re imprints or recordings rather than actual manifestations, which may be why many refer to them as apparitions. 
 
But there are problems with that line of thinking.  One of which is the lack of a media on which the image is imprinted.

As we’ve discussed, the residual spirit of a human being or animal is imprinted on a location, a house for example.  Whereas the sea, being an ever changing environment, would seem unable to sustain an imprint for lack of a solid base, making the existence of a ship like the previously discussed Flying Dutchman unlikely.

Personally it seems to me that so many of the things we investigate are unlikely that “Unlikely” loses its meaning in this context.

Many will tell you adamantly that inanimate hauntings are almost always one time appearances.  However when involved in these discussions I always ask for examples, because the ones I’m aware of are almost all long standing stories.  Again you can point to the Flying Dutchman, but there are countless stories of ghost trains and automobiles and to the best of my knowledge they’re all recurring.

I believe this lends credence to the possibility that we’re in fact not dealing with a spirit at all, but possibly something referred to as a Time Slip.

In any case, it appears that the only agreed upon characteristic of this phenomena are that they are rarely if ever interactive.