Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Furnishings and Equipment (hierarchy name)
4. Transportation Vehicles (hierarchy name)
5. vehicles (transportation)
6. watercraft
7. [watercraft by specific type]
8. [watercraft by operating environment]
9. [watercraft by displacement]
10. subsurface watercraft
11. submersibles
12. unmanned underwater vehicles

Anotations

Scope note:

Unmanned underwater robots used for survey missions such as detecting and mapping submerged wrecks, rocks, and obstructions (with the use of sensors) that can be a hazard to navigation for commercial and recreational vessels. They complete these missions without operator control. For similar devices controlled by an operator remotely, use 'remote submersibles.'