Submarines

Submarines are essential to both the defense of Endros and the daily life of its Merfolk colonies. The Navy operates over two hundred of them, and they are responsible for the bulk of its combat against demonic threats. Water displacement magic allows rapid descent, ascent, turning, and acceleration without pressurization issues, and most vessels are flooded for Merfolk crews, with Seahold cabins added where land-dwellers must travel aboard.

Common Submarines

Naval Submarines: The Navy's combat vessels, ranging from small patrol craft to heavy warships designed to hunt aquatic demons.
Merchant Submarines: Cargo vessels that carry goods between Merfolk colonies and coastal ports, often hauling standardized buoyancy-class crates along the Hydrolanes.
Reefline Submarines: Public passenger vessels that carry visitors through the Merfolk colonies beside each Tidewalk. Land-dwellers use Aquamasks unless the vessel includes Seahold cabins.
Cargo Sleds: Small open sleds used to move freight within colonies, especially along Jetlanes.
Manta Skis: Fast, agile single-person submersibles shaped like manta rays, popular among couriers and wealthy Merfolk.

The Kraken Heart

The Kraken Heart is the fastest, most dangerous submarine in the world, and the Navy's most prized weapon. Somewhat resembling a squid's body, it has three giant tentacle-like appendages powered by magic. It is officially recognized as a World Wonder that took nearly fifty years to complete, constructed exclusively by elite Aethertech engineering teams with the direct involvement of Aedron, God of Crafting.

Only sufficiently powerful Deepwater Merfolk may pilot it. The submarine emphasizes speed, stealth, and surgical strike precision, and its rotation and acceleration are so fast that, despite stabilizing enchantments, they can disorient untrained passengers. Its tentacles allow an extreme turning radius and can grip and crush with tremendous force. Its primary weapon, famously named "Poseidon's Trident," is so devastating that fewer than seven demonic threats are known to have survived a direct hit. Many believe that with Nautilus or Ursula fighting at its side, it could finally destroy Morvasha, the Drowned Mother.

Its core body is 30 meters long and 10 meters in diameter, and its three tentacles reach an additional 35 meters, for a total length of 65 meters. The tentacles are piloted separately from the main body, and are considered the most prestigious piloted positions in Endros.

The Stingray

The Stingray is the Navy's foremost scouting vessel, built for early threat detection rather than combat. Its flat body and enchanted mechanical tail allow it to turn with remarkable speed, and it is the second fastest submarine in the fleet after the Kraken Heart. Its detection systems can sense communication signals up to 200 kilometers away, and ships, submarines, large lifeforms, aquatic sorcery, and significant water disruptions up to 150 kilometers away. It can also broadcast enhanced emergency signals, making it invaluable for relaying warnings across the sea.

Undertow

Undertow is a stealth submarine that shadows Endros's most valuable ships, unseen unless it is needed. Its weapons and armor are designed to dominate the water around it, and it moves so quickly that enemies beneath the waves have little chance to escape or resist. Swimmers can be drawn directly into its sealed capture pods, making it devastating against the Warlock Merfolk that pirate crews rely on to contest the waters below a ship.

Once the waters are cleared, Undertow locks onto the target's hull with powerful clamps, anchoring it in place. Without anyone left underwater to remove them, the pirates have no way to break free, and Undertow can take all the time it needs to decide how to finish the encounter. A Siren strike team aboard can board the ship from below, allowing Undertow to capture vessels and crews intact. Only one Undertow exists, but no one knows which ship it guards, and the threat of its presence alone deters pirates from attacking high-profile targets.

Tessera

Tessera is the Navy's undersea construction vessel, carrying Undertide Industries engineers to build and maintain the infrastructure beneath Endros's seas. It places and repairs Hydrolane Markers, cultivates Jetlanes, lays seafloor wards and enchantments, and restores Reef Walls after demonic attacks. Though rarely celebrated, it is among the most important vessels in the Navy, and much of the safety and speed of undersea travel depends on its work.

The Tidebreaker

The Tidebreaker is a luxury submarine designed with hybrid environments suited to both aquatic and non-aquatic species. It can be boarded easily from land or sea, serving as a diplomatic convoy with the Merfolk. Its magic allows air to be extracted and recycled from the water. The submarine is 20 meters long and 7 meters in diameter, with two decks averaging roughly 3 meters high. The upper deck offers a grand, cruise-like experience with vaulted, open-sea windows and water chambers for Merfolk guests, and wealthy tourists often pay to experience the sights beneath the ocean. The lower deck holds living quarters, operational and navigational centers, and storage.