Mauluo - Class Submarine

Large type of purposed organism designed to allow Harki to launch stealth attacks on other warships by diving to immense depths which would kill most other purposed organisms.

The Mauluo, named after the planet Mauluo, of the Beta Targos System, is powered by a highly advanced antimatter reactor like other Hyperion Federation warships, though the Mauluo - class can neutralise its own energy signature at the cost of a lot of energy. It also needs to obtain matter plasma from the wider HF as nutrients.

The ship can dive to the extreme depth of 10 km underwater in a gravity of 10 m/s. At such extreme depths, the environment has no light at all, and incorporating bioluminescent organs would reveal its location. Instead, the ship relies on a sonar device, similar to mechanical equivalents. Also, the extreme pressure at this depth would crush any cavity that holds gas or vacuum. It relies on a set of gills for respiration rather than lungs to help it remain in depth for longer, so the ship can continue to obtain oxygen when dived. The ship holds oxygen and matter plasma in its blood and has no organs meant for storage other then the crew cockpits, which can seal the crew and collapse itself.

It has a number of torpedo launchers designed to surface rapidly despite their organic nature to hit a target on the surface or at higher depths. Because it is designed for stealth rather than taking hits, the warship has no CIWS turret equivalents, but it does have a shield which can take some of the water pressure away from the ship, as well as take a small amount of fire.

The extreme pressure would kill any harkas crew inside the ship. Even extremely strong materials would be damaged by the pressure, so the crew are completely sealed in a material which takes the vast majority of the pressure. The crew's bodies are linked directly to the bloodstream of the ship so that they can continue to function even though they cannot breathe on their own while completely sealed. They are also linked to the ships nervous system and interface with the ships brain directly and each assume some control over the body of the entire warship, and such coordination between many different brains can be exceptionally difficult to master, obviously increasing training times and costs. Communication between crew brains is accelerated massively as the ships nervous system can carry information much faster than speaking.

Even systems like its cardiovascular system would need modifications at this depth because it could collapse if the pressures become too great, so the Mauluo is designed to have veins which collapse under huge pressure, but the blood pressure inside the veins increases immensely as well. This takes time for the ship to become used to. It is known that the ships size actually decreases as it dives to extreme depths mainly because of this, while keeping the mass constant. Its heart is massive to compensate for this, and it is very loud which would reduce morale but the crew will be neurally linked to the ship anyway and will not be able to use their own hearing senses, instead relying on that of the ship. Listening to the heartbeat is one way to detect the ship, but is difficult due to its depth (any enemies trying to find it this way would need to filter ambient sounds very efficiently) and will not give the enemy an accurate bearing of the mauluo's location.

While surfaced, it has a length of about 700m but while dived it reduces to about 450 m. Its metabolism rate also slows down, and the ship must also make this change to its crew to conserve oxygen.

Because of the extreme physiological changes the ship needs to make to dive, it cannot surface quickly or it will get decompression sickness along with its crew. As such, making emergency surface maneuvers is not possible. This makes the warship relatively niche compared to mechanical versions, but it can dive deeper, remain more effective at stealth and its crew coordination is incredibly efficient. As such, organic submarines would still have strategic uses in the military. While they are adapted to deep travel and if they are in relatively shallow depths (such as those at about 1 km), they can survive hits from depth charges and similar weapons because they can withstand the pressure.