Appendix
The Codex
Encyclopedic entries on the world: places along the shelf and the deeper trenches, the people who live in them, the species that share their water, the technologies that get the survey there, and the words for what is found. Entries that appear in the manuscript carry a folio reference.
Anchor page
Diving & habitats
Real-world depth tiers, ADS, saturation, submersible classes — the realism that grounds everything else.
10 entries
History
From the Surface Crisis to the present survey, dated and dispassionate.
30 terms
Glossary
Quick-reference terminology — diving, zoological, Pelagine.
4 entries
Language
Pelagine phonemes, phrases, and a particle that resists translation.
Places
30 m – 90 m · contestedfol. 29v · Ch. V
The Lipless Reach
A drowned coastal stretch at recreational and technical diving depth, used as a site of pilgrimage by the Surfaceborne and surveyed intermittently by the Conservancy.
40 m – 80 m · humanfol. 2v · Ch. I
Karrowin Halt
A small human anchorage at the upper shelf margin, lightly maintained and the most accessible of the outer stations to recreational visitors from the surface.
80 m – 110 m · contestedfol. 27v · Ch. V
The Reliquary at Pell
A flooded cathedral at technical diving depth, held as a relic by the Surfaceborne and the most-documented ruin in the current archive.
80 m – 180 m · humanfol. 3r · Ch. I
Varangurd Anchorage
A human habitat cluster anchored to the outer shelf, the busiest waystation between surface and saturation depths.
90 m – 140 m · contestedfol. 27r · Ch. V
Lethewards Drift
A ruined habitat cluster on the outer shelf, abandoned during the Subsidence Wars and surveyed but never resettled.
100 m – 140 m · humanfol. 5r · Ch. I
Helmsward Crossing
A working saturation-depth corridor along a maintained cable route, lightly inhabited and kept operational by the Filament Guild.
120 m – 180 m · contestedfol. 26v · Ch. V
The Boneward
A saturation-depth memorial structure built above a drowned coastal city, maintained by the Bathymetric Conservancy as a site of formal witness rather than commemoration.
360 m – 410 m · contestedfol. 14v · Ch. III
Marker IX (Liminal Threshold)
One of nine designated meeting stations in the contested band between three and five hundred metres, used for formal Pelagine–human contact.
380 m – 420 m · contestedfol. 9v · Ch. II
The Brassgate
A contested-zone meeting station at ADS depth, maintained jointly by the Conservancy, the Tyrian Court, and the Pearled Council as the formal point of inter-faction contact.
540 m – 600 m · humanfol. 8v · Ch. II
The Meridian Spine
The deepest permanent human city, a sealed-hull enclave between five hundred forty and six hundred metres accessible only by atmospheric diving suit.
1,050 m – 1,200 m · wildfol. 19v · Ch. IV
The Black Lung
A methane vent field on the deep shelf floor, observable only by submersible and host to extremophile communities that include tide-coral formations and resident mantle-singers.
2,200 m – 2,500 m · pelaginefol. 17r · Ch. III
The Silent Chord
The principal seat of the Pearled Council, a Pelagine settlement between two thousand two hundred and two thousand five hundred metres known for its distinctive acoustic signature.
3,200 m – 4,100 m · pelaginefol. 20v · Ch. IV
The Trench of Avals
A long bathyal trench, seat of the Tyrian Court and the most-mapped Pelagine settlement reachable by submersible.
3,700 m – 3,900 m · pelaginefol. 22v · Ch. IV
The Vault of Hours
A Tyrian Court archive at bathyal depth, observable only through submersible portholes and associated with the Pelagine concept of duration.
8,100 m – 8,400 m · wildfol. 23v · Ch. IV
Ginnungap Trench
A hadal trench reaching to eight thousand four hundred metres, visited twice in the past decade by DSV expedition and otherwise uncharted below the abyssal approaches.
Species & flora
30 m – 100 m · faunafol. 11v · Ch. II
Iris snail
A small kelp-blade gastropod with a brilliantly iridescent muscular foot, common at recreational depths near kelp-forest habitats and harmless to divers.
30 m – 120 m · florafol. 6v · Ch. I
Phosphor-kelp
A shelf kelp that produces faint bioluminescence on moonless nights, common near Karrowin Halt and the Lipless Reach and visible to recreational divers in dark-water conditions.
40 m – 220 m · faunafol. 3v · Ch. I
Kelp-fanwing
A slow, ray-shaped grazer of the upper shelf kelps, common around Varangurd and tolerated as a resident animal.
800 m – 1,400 m · florafol. 12r · Ch. II
Tide-coral
A slow consortium of skeletonised flora and tide-driven microbes found near vent fields, quiescent in darkness and faintly phosphorescent when disturbed.
1,200 m – 3,500 m · faunafol. 28r · Ch. V
Glass-shawl medusa
A near-translucent twilight zone jellyfish observed in open midwater at the boundary of the Twilight Belt, trailing ribbon-like tentacles many metres in length.
1,500 m – 3,500 m · faunafol. 23r · Ch. IV
Ink-veiled cephalopod
A midwater cephalopod of the Twilight Belt that deploys an absorptive ink curtain rather than a dispersive cloud, observed near the Silent Chord.
1,800 m – 3,200 m · pelaginefol. 15v · Ch. III
Mantle-singer
A large, slow-moving organism of the lower Twilight Belt associated with Pelagine settlements, recognised by the survey for its structured low-frequency vocalisations.
2,800 m – 5,800 m · faunafol. 20r · Ch. IV
Eyeless lurker
A bathyal ambush predator native to the trench walls of Avals and similar features, known principally from submersible observation.
3,000 m – 5,000 m · faunafol. 30v · Ch. V
Plumed gulper
An eel-like bathyal predator bearing a dramatic plumed dorsal display, observed in slow deep water near the Vault of Hours by submersible.
3,700 m – 3,900 m · pelaginefol. 18r · Ch. III
Vault-eel
A Pelagine organism associated with the Vault of Hours, observed only from submersibles and at distance, whose function within the Pelagine archive the author does not pretend to understand.
4,000 m – 8,500 m · faunafol. 24r · Ch. IV
Cliff-walker
A jointed wall-clinging arthropod observed across both the Midnight and Hadal zones, documented at the Ginnungap Trench in rare hadal survey passes.
4,000 m – 6,000 m · faunafol. 21r · Ch. IV
Lampgill anglerfish
A midnight zone ambush predator distinguished by bioluminescent gill-rakes rather than a dorsal lure, observed only from submersibles at depth.
Peoples & polities
research bodyfol. 11r · Ch. II
The Bathymetric Conservancy
The human research and survey body responsible for mapping, diving operations, and Pelagine liaison from the outer-shelf anchorages.
guildfol. 9r · Ch. II
The Filament Guild
A human working guild responsible for the cables, repeaters, and lighting that make the long submerged corridors usable.
pelagine polityfol. 17v · Ch. III
The Pearled Council
A Pelagine polity centred on the Silent Chord, distinct from the Tyrian Court in voice and in the depth at which it consents to be heard.
human enclavefol. 30r · Ch. V
The Surfaceborne
A small ascetic order of humans who refused to descend, kept to a remaining island chain, and tend the drowned coast as relic.
pelagine polityfol. 15r · Ch. III
The Tyrian Court
A Pelagine polity centred on the eastern wall of the Trench of Avals; the principal interlocutor of the human survey since first contact.
Technology
diving
ADS — the Newtsuit lineage
The articulated atmospheric diving suits used by the survey from roughly three hundred to seven hundred metres.
communications
Hydrophone networks
The passive listening grids that monitor the human shelf and the bathyal approaches; not surveillance, exactly, but the closest the survey has.
diving
Saturation diving systems
The pressurised-confinement protocol used by long-duration human work between roughly one hundred and three hundred metres.
submersible
The DSV class hierarchy
A three-tier classification of crewed submersibles by depth rating, used by the survey for tasking, insurance, and crew certification.
surface link
The Helmsward cable
A single fibre-and-power conduit running from the surface link down to Varangurd and on along the shelf to the deeper enclaves.