Development and Operation of a Free-Fall Type Glass Sphere Underwater Observation System with Suspended Cable in the Seto Inland Sea

We have developed a free-fall type glass sphere underwater observation system with suspended cable. The developed observation system is quite simple to construct and is able to operate at deep sea because the system is structured by glass sphere. The glass sphere has high endurability. Due to no motion system like thrusters, the position of a free-fall type underwater observation system is not clear. And hence, we propose the operation of a free-fall type underwater observation system with a suspended cable like a zipline. To make the position of the system more precise, an inertial measurement unit (IMU) is installed inside the system. A router is also installed inside the system to obtain underwater pictures via a LAN cable. The observation system, which is named UWOS (Under Water Observation System), was operated in the Seto Inland Sea. It was found that the UWOS indicates the possibility of a free-fall type glass sphere underwater observation system with a suspended cable.