To take samples from the seabed in hazardous, unapproachable waters, we have developed a new observation system that can take samples from the seabed by remote control. Operating this system in such hazardous waters presents the risk of losing it. Therefore, we designed and built a simple and cheap prototype based on existing technologies and knowhow JAMSTEC has obtained at sea. We conducted sea trials using this prototype and demonstrated that it can take samples from the seabed by remote control through the Wi-Fi communication.