2HE-X Submarine

Special Diver Submarine 2HE-X

Our strive for constantly improved, even more exclusive offers for ambitious Tec-divers, gave us the idea of the 2HE-X, a special diver submarine designed to meet the particular needs of technical diving. This project is currently the subject of a feasibility study, or respectively a proof of concept. The 2HE-X allows divers to descend directly to the dive destination at 1 bar without pressure of time.

A bow made of acrylic glass offers an excellent panoramic view of the diving object. As soon as all details are explored and all divers are ready, they compress in a multi-stage pressure chamber (dry) up to ambient pressure and can then dive out of the diver’s lock via a moon pool from the submarine. During the whole dive the submarine remains in the depth on site. After all divers have returned to the boat, they decompress in the best possible way (again dry) – while the sub ascends, or even longer afterwards, when the submarine is already back at the surface.

The main differences to a conventional submarine – research submarine or a military submarine – are several sections besides the constant pressure section (front-most, green). Those sections can be pressurized between 50 bar below and 30 bar above surrounding pressure (yellow, orange, red). These multi-stage chambers allow to decompress two groups of divers independently of each other in the most effective way. If necessary, the diving physician or a support / rescue team can be transferred in or out at any time without impairing the decompression quality of the other divers.

In-line with our philosophy, the 2HE-X will also be operated as a zero-emission vehicle. On the surface, the submarine forms the center hull of a “carrier trimaran”. Besides sailing any distance with the wind, a photo-voltaic system and the main propulsion of the submarine in reverse operation, as well as recuperation processes during the relaxation of compressed diving- and working gases will be used to generate sufficient power for the entire energy demand of the 2HE-X.

Preliminary key data of the 2HE-X
  • Maximum diving depth:  500 m
  • Length overall Submarine / Tri: ~15 m / ~24 m
  • Pressure vessel diameter: ~2.4 m
  • Displacement submerged: ~45 m³
  • Crew / Diver: 2 / 9

Diagram Sections: Control room (1 bar constant, green), chamber 1 (1-35 bar, yellow), chamber 2 (1-35 bar, orange), chamber 3 / diver’s lock (1- 35 bar, red), engine room (blue)


Compared to a conventional Tec-dive, this concept offers several unique performance and safety advantages:

  • Safe dry descents and ascents or compression and decompression
  • Accidents due to drowning (oxygen toxicity!) are impossible
  • Optimal supply with beverages and food prevents dehydration
  • Controlled decompression rate, corresponds to the “ideal ascent”
  • Uncontrolled rapid ascent impossible
  • Ideal decompression gases, with continually varying fractions (helium, oxygen, nitrogen, etc.)
  • Accidents due to the use of wrong decompression gases impossible
  • Medical monitoring and intervention possible at any time (physician can be transferred in and out)
  • Rescue teams can be deployed at any time (standby divers can swim out within the shortest possible time)
  • Practically unlimited supply of diving and decompression gases directly at the spot
  • Extended bottom times due to shortened “descents “
  • Two groups of divers can be treated independently

Compared to a conventional Tec-dive, this concept offers several unique performance and safety advantages. The basic requirements for the realization of emission-free operations – like the 2HE-2 – are good sailing abilities of the carrier. In contrast to a “normal” sailing trimaran, our construction must also work without the center hull, i.e. as a catamaran, and be able to follow the submarine under all conditions. Furthermore, the high mass of the middle hull, which is a multiple of the usual, is a challenge. In addition to its function as the main surface propulsion and energy supply system for the submarine, the carrier also serves as the important means for gas storage facility, surface support station, crew quarters and much more.

Costs / Profitability

As there have been no comparable designs yet, the entire design is pioneering work and therefore particularly work- and cost-intensive. In addition, high quality building materials are needed due to the intended immersion depth of 500 m. At present, we expect total construction and development costs of around 15 Million Euros, a payback period of 6 years and a service-life until the first general overhaul of 15 years.