A Submersible (潜水艇, Sensui-tei), more specifically Subspace Submersible (亜空間潜水艇, Akūkan Sensui-tei), is a type of spaceship which is designed to dive into regions of subspace which regular craft cannot normally reach .
Submersibles are capable of diving into subspace from regular space and are capable of safely passing through regions deeper than the routes normally used for FTL travel, which normal spacecraft cannot safely pass through .
Though submersibles are designed to dive deep into subspace, there are limits as to how far they can dive and they cannot safely dive below that depth limit. On some submersibles there are automatic emergency systems which will force the craft to surface if it exceeds its limits .
Aside from propulsion and diving systems, submersibles may also possess other systems to assist their operations in deep subspace .
Those who dive into deep subspace in submersibles are referred to as Subspace Divers (亜空間ダイバー, Akūkan Daibā), or Divers (ダイバー, Daibā) for short .
- Great Depth XIII
- Hora 
- Ryu-Oh 
- Ballade 
- Éclat 
- Octopus II 
- Day-Tripper