Olran - Class Submatine

A large type of organic submarine, notable for being the first successful design used by the first terrestrial Harki seafarers who wanted to explore the depths of the ocean. This was well before the Hyperion Federation made contact with the harki for the first time, and their knowledge of biology was far less advanced.

The Olran - class is named after an area of ocean on Mauluo where it was initially designed to explore. As harki knowledge of deep sea life became better understood, their submarine purposed organisms improved significantly, but at this point they did not yet have as much control over an organism's body as modern harki, so it still possesses systems like a digestive system and even a reproductive system. As such, these highly crude initial versions of a submarine still had to eat food and could reproduce with each other unlike modern ships like the Mauluo - Class Submarine.

The crew were placed in a number of small organs designed to house them. The Olran and later, virtually all organic submarines, became known to be incredibly difficult to control because the crew had to neurally link with the brain of the ship as well as other crew members, thus lose control of their own body but gain some control of that of the submarine. Their chambers were filled with water, and the crews' esophagi and lungs were collapsed at all times while blood was supplied to them from the ship itself. This was to eliminate any gas within the ship which massively improves the depth at which it can travel, and its stealth. The ship was required to sustain the bodies of the crew and keep them alive. If a crew member died, the resulting trauma would be shared across the whole ship and they would have to adapt to this loss of control or die in battle. They have thus evolved slightly to protect the crew chambers, but ultimately the harki ability to modify the ship's genome increased this method of protection much faster. 

It is entirely possible to remain part of the Olran for one's whole life, to the point where some suggested the possibility of the crew becoming inseparable from the ship if it was allowed to evolve like this. 

The entire organism is several hundred meters long, and required large amounts of food because of this large size. Sometimes, the Olran would scavenge the local ecosystem for food, the crew being taught how to hunt while in control of the ship's body. This was only required on long missions though, as they could be fed while docked.

As with the Mauluo, its heartbeat could be heard by the crew and by any very sensitive senses listening for it. It was much quieter though, because the ship does not dive as deep as the Mauluo and thus does not require its blood pressure to increase. Its digestive system creates noise too, but its usually quieter than the heart and the crew cannot use their ears while in control of the submarine anyway. 

The ships own instinct might have an impact on any missions it was sent to complete. For example, reproductive instincts or those caused by its gut flora could interfere with some missions which has led to incidents, so a new type of organic submarine was necessary. Military and scientific variants were created with more advanced knowledge of deep diving physiology and the Olran - class divergently evolved into several different species with other uses and which could handle some situations better, with more advanced physiology. Notably, several species had more efficient digestive processes, allowing them to use less food for the same missions.

After the ship was fitted with devices that could create sound intentionally (like vocal cords), it could make contact with those harki deep under the water and allow for trade between these subspecies. The captain of the ship was often made to negotiate diplomatically, but sometimes diplomats were placed into these ships who would instead negotiate with the underwater lineages.