Shipworm

The vessel, though her masts be firm,
Beneath her deck she bears a worm;
Around the cape, across the line,
Till fields of ice her course confine;
It matters not how smooth the breeze,
How shallow or how deep the seas,
Whether she bears Cerulean twine,
Or in her hold Amberline wine,
Or Antarian teas, or Dukari hides,
In port or quarantine she rides;
Far from Keymouth's blustering shore,
The ocean's worm her hulk shall bore,
And sink her in the Azure seas,
Twine, wine, and hides, and Antarian teas.

— Hubert Deepburrow Thorow

Shipworms are marine molluscs with long, soft bodies. and are notorious for boring into (and commonly eventually destroying) wood that is immersed in sea water, including such structures as wooden piers, docks and ships.
They drill passages by means of a pair of very small shells borne at one end, with which they rasp their way through. They are sometimes called pileworms or "termites of the sea".
The biological consumption of the wood by the worm causes hydrogen sulphide to be emitted by the creature, meaning that ships riddled with the parasite often have the distinctive smell of rotten eggs.
All wooden vessels that sail on The Azure Sea and the world's oceans are affected by the worms, and indeed, if they are not careened roughly every three months the damage caused can render their hulls leaky and unseaworthy. Many ships have been sunk due to the extensive damage that untreated shipworms can cause.
Removed from its burrow, the fully grown seaworm ranges from several centimetres to about a metre in length, depending on the species variety. There are rumours of giant shipworms living in the deeper parts of the sea, which can reportedly reach many metres on length.

Shipworms in the hull of a ship by Blickwinkel

Type

Parasite

Lifespan

1-3 years

Average Length

up to 1 metre

Geographic Distribution

• The Azure Sea